Barriers to entry are defined by Bain (1956) as conditions that allow established firms or incumbents to earn abnormal profits without attracting entry (see Box 1.1). Stigler (1968, p. 67) defines entry barriers as 'a cost of producing (at some or every rate of output) which must be borne by a firm which seeks to enter 进入壁垒是由贝恩（1956 年）定义的，指的是使得已建立的公司或现有公司能够在不吸引其他公司进入的情况下赚取异常利润的条件（见框 1.1）。斯蒂格勒（1968 年，第 67 页）将进入壁垒定义为“生产成本（在某种或每种产出率下）必须由寻求进入的公司承担的成本”。
an industry but is not borne by firms already in the industry'. Spulber (2003, p. 55) defines an entry barrier as 'any competitive advantage that established firms have over potential entrants'. 一个行业，但不是由已经在该行业的公司承担的。Spulber（2003 年，第 55 页）将进入壁垒定义为“已建立公司对潜在进入者拥有的任何竞争优势”。
Section 12.2 identifies the principal types of barrier to entry. These include barriers that arise from economies of scale, or from an absolute cost advantage held by an incumbent over an entrant, or from product differentiation. Other barriers to entry include legal barriers and geographic barriers, which create difficulties for foreign firms attempting to trade in the domestic market. Many of the factors that give rise to the barriers to entry may be beyond the direct control of the incumbent firms. However, sometimes incumbents are able to take steps that increase the difficulties that new entrants will have to overcome if they are to establish themselves on a profitable basis. In other words, incumbents can implement entry-deterring strategies in an attempt to increase the size or height of barriers to entry. The entry-deterring strategies discussed in Section 12.3 include limit pricing, predatory pricing, and brand proliferation. 第 12.2 节确定了进入壁垒的主要类型。这些包括由规模经济产生的壁垒，或者由现有公司对新进入者拥有的绝对成本优势产生的壁垒，或者由产品差异化产生的壁垒。其他进入壁垒包括法律壁垒和地理壁垒，这些壁垒给试图在国内市场交易的外国公司带来困难。导致进入壁垒的许多因素可能超出现有公司的直接控制范围。然而，有时现有公司能够采取措施，增加新进入者必须克服的困难，以便他们能够建立在盈利基础上。换句话说，现有公司可以实施阻止进入的策略，试图增加进入壁垒的规模或高度。第 12.3 节讨论的阻止进入的策略包括限价、掠夺性定价和品牌扩张。
Paradoxically, the extent of barriers to exit may be an important factor determining the incentive for new firms to enter. It is costly to exit if production requires sunk cost investment expenditures. Sunk costs are costs that cannot be recovered if the firm subsequently decides to close down or exit. For example, expenditure on capital equipment that can only be used to manufacture the product in question and will be scrapped if the firm exits is an example of a sunk cost expenditure. Entry is therefore riskier in cases where the entrant is unable to recover its costs if its decision to enter subsequently turns out to be unsuccessful. 悖论的是，退出壁垒的程度可能是决定新公司进入动机的重要因素。如果生产需要沉没成本投资支出，那么退出将是昂贵的。沉没成本是指如果公司随后决定关闭或退出，就无法收回的成本。例如，对只能用于制造特定产品并且如果公司退出将被报废的资本设备支出就是沉没成本支出的一个例子。因此，在新公司无法收回成本的情况下，如果其进入决策后结果不成功，那么进入就会更加风险。
Even if the entrant is confident it can succeed, perhaps because it knows it can produce at a lower average cost than an incumbent, barriers to exit facing the incumbent may still be an important consideration for the entrant. If the incumbent has already incurred significant levels of sunk cost expenditure (for example, by building excess capacity), so its exit barriers are high, the incumbent is likely to resist attempts by the entrant to capture part or all of its market share, perhaps by initiating a price war. If there has been no sunk cost expenditure and exit barriers are low, the incumbent threatened by competition from a low-cost entrant might simply prefer to withdraw quietly. If entrants take account of the probable reaction of incumbents before deciding whether or not to enter, the extent of exit barriers facing incumbents may be an important factor influencing the entry decision. Section 12.4 examines ways in which incumbents can signal commitment to defend an established position of market dominance by deliberately increasing their sunk cost expenditure. 即使参与者有信心可以成功，也许是因为它知道自己可以以比现有参与者更低的平均成本生产，但面临现有参与者的退出壁垒仍可能是参与者的一个重要考虑因素。如果现有参与者已经承担了大量的沉没成本支出（例如，通过建设过剩产能），使其退出壁垒很高，那么现有参与者可能会抵制参与者试图夺取其部分或全部市场份额的尝试，也许会发起价格战。如果没有发生沉没成本支出，退出壁垒很低，那么受到来自低成本参与者的竞争威胁的现有参与者可能只是选择悄悄地退出。如果参与者在决定是否进入之前考虑现有参与者的可能反应，那么面临现有参与者的退出壁垒的程度可能是影响进入决策的一个重要因素。第 12.4 节探讨了现有参与者如何通过故意增加其沉没成本支出来表明捍卫市场主导地位的承诺。
Contestable markets theory is examined in Section 12.5. In industries where barriers to entry are surmountable, the threat of entry may keep prices close to the competitive level, even if there are few firms and the industry appears to be highly concentrated. Contestable markets theory breaks the direct link between the number and size distribution of sellers and the extent of market power or the discretion incumbents have in setting their own prices. Section 12.6 examines a more dynamic view of entry and market evolution over the long run. Entry is seen as a disequilibrating force that plays a central role in shaping the evolution of market or industry structure in the long run. The chapter concludes in 可竞争市场理论在第 12.5 节中进行了研究。在那些可以克服进入壁垒的行业中，即使只有少数公司，行业看起来高度集中，进入的威胁也可能使价格保持接近竞争水平。可竞争市场理论打破了卖方数量和规模分布与市场力量或现有公司在定价方面的自由裁量之间的直接联系。第 12.6 节探讨了对进入和市场演变的更动态视角。进入被视为在长期内塑造市场或行业结构演变中发挥核心作用的一种失衡力量。本章在第 12.7 节总结，简要回顾了一些关于进入决定因素和进入壁垒主要来源的实证证据。
Section 12.7 with a brief review of some of the empirical evidence on the determinants of entry and the main sources of barriers to entry. 第 12.7 节简要回顾了一些关于进入决定因素和进入壁垒主要来源的实证证据。
12.2 Types of barrier to entry 12.2 进入壁垒类型
The types of barrier to entry examined in this section are economies of scale, absolute cost advantage, product differentiation, switching costs, network externalities, and legal and geographic barriers to entry. Carlton (2004) and McAfee et al. (2004) provide further discussion on classifying and measuring entry barriers. 本节中考察的准入壁垒类型包括规模经济、绝对成本优势、产品差异化、转换成本、网络外部性以及法律和地理准入壁垒。Carlton（2004）和 McAfee 等人（2004）进一步讨论了对准入壁垒的分类和衡量。
Economies of scale 规模经济
Economies of scale can act as a barrier to entry in two ways. First, there is an entry barrier if the MES is large relative to the total size of the market. As shown earlier, MES is the output level at which all potential economies of scale have been exploited, and the firm is operating at the lowest point on the LRAC function (see Section 2.2). The nature of the technology may be such that firms must claim a large market share in order to produce at the MES. A natural monopoly, in which long-run average costs decrease as output increases over all possible output levels the market can absorb, is the most extreme case. In a natural monopoly average costs are minimised if one firm occupies the entire market (see Section 3.4). This situation tends to arise in industries where fixed costs are high relative to variable costs. 规模经济可以通过两种方式成为准入壁垒。首先，如果最小有效规模（MES）相对于市场总规模较大，则存在准入壁垒。如前所述，MES 是所有潜在规模经济被利用的产出水平，公司在 LRAC 函数的最低点运营（见第 2.2 节）。技术的性质可能是这样的，即公司必须在 MES 处拥有较大的市场份额才能生产。自然垄断是最极端的情况，即长期平均成本随着市场能够吸收的所有可能产出水平的增加而降低。在自然垄断中，如果一家公司占据整个市场，则平均成本最小化（见第 3.4 节）。这种情况往往出现在固定成本相对于可变成本较高的行业中。
The second way in which economies of scale can act as an entry barrier is when average costs associated with a production level below the MES are substantially greater than average costs at the MES. This is illustrated in Figure 12.1. In both industry and industry , the penalty for producing at 50 per cent of the MES is . This penalty is much greater in industry than in industry , due to the difference in slope between the two LRAC functions. 规模经济作为进入壁垒的第二种方式是，当与 MES 以下的生产水平相关的平均成本远远高于 MES 处的平均成本时。这在图 12.1 中有所体现。在 行业和 行业中，以 MES 的 50%生产的惩罚是 。由于两个 LRAC 函数之间斜率的差异，这种惩罚在 行业中比在 行业中要大得多。
Figure 12.1 Economies of scale as a barrier to entry 图 12.1 规模经济作为进入壁垒
Table 12.1 Economies of scale as a barrier to entry 表 12.1 规模经济作为进入壁垒
Industry
Increase in average cost if 如果在 MES 的 50%运行，平均成本增加
operating at 50% of MES
Motor vehicles 机动车
Chemicals
Metals
Office machinery 办公设备
Mechanical engineering 机械工程
Electrical engineering 电气工程
Instrument engineering 仪器工程
Paper, printing and publishing 纸张、印刷和出版
Rubber and plastics 橡胶和塑料
Drink and tobacco 饮料和烟草
Food
Footwear and clothing 鞋服
Source: Adapted from Pratten (1988), Table 5.5, pp. 88-92, (O) European Union, . 来源：改编自普拉滕（1988 年），表 5.5，第 88-92 页，（O）欧盟， 。
Economies of scale present the potential entrant with a dilemma. Either the entrant accepts the risk associated with large-scale entry in order to avoid the average cost penalty, or the entrant enters at a smaller scale and absorbs the average cost penalty. Large-scale entry is risky because the expansion in industry capacity might disrupt an established industry equilibrium, depressing prices and inviting retaliatory action from incumbents. On the other hand, small-scale entry may not be viable, because the average cost penalty may make it impossible for the entrant to operate profitably alongside incumbents already producing at (or beyond) the MES. 规模经济给潜在进入者带来了两难选择。潜在进入者要么接受与大规模进入相关的风险，以避免平均成本惩罚，要么以较小规模进入并吸收平均成本惩罚。大规模进入是有风险的，因为行业产能的扩张可能会扰乱已建立的行业均衡，压低价格并引发现有企业的报复行动。另一方面，小规模进入可能不可行，因为平均成本惩罚可能会使潜在进入者无法与已经在 MES 水平（或以上）生产的现有企业一起盈利运营。
Pratten (1988) provides some empirical estimates of the extent to which economies of scale acted as a barrier to entry for a number of European industries in 1986. Table 12.1 shows estimates of the additional average cost that would be incurred by operating at 50 per cent of the MES, in comparison with the average cost incurred when operating at the MES expressed as a percentage of the latter. Pratten（1988）提供了一些关于规模经济在 1986 年对一些欧洲行业构成进入壁垒程度的实证估计。表 12.1 显示了在以 MES 的 50%运营时将产生的额外平均成本的估计，与在以 MES 运营时产生的平均成本相比，后者以百分比表示。
Absolute cost advantage 绝对成本优势
An incumbent has an absolute cost advantage entry barrier over an entrant if the LRAC function of the entrant lies above that of the incumbent, and the entrant therefore faces a higher average cost at every level of output. This situation is illustrated in Figure 12.2. 如果新进入者的 LRAC 函数高于现有企业的 LRAC 函数，则现有企业具有绝对成本优势的进入壁垒，因此新进入者在每个产出水平上面临更高的平均成本。这种情况在图 12.2 中有所体现。
There are several reasons why an entrant may operate on a higher LRAC function. First, an incumbent may have access to a superior production process, hold patents, or be party to trade secrets. For example, the Monopolies and Mergers Commission (1968) estimated that it would take an entrant to the cellulose fibre industry between five and seven years to catch up with state-of-the-art production technology. Patenting involves the deliberate creation of a property right for 新进入者可能在更高的 LRAC 函数上运营的原因有几个。首先，现有企业可能可以获得更优越的生产工艺，拥有专利或参与商业秘密。例如，垄断和并购委员会（1968 年）估计，新进入者进入纤维素行业需要五到七年的时间才能赶上最先进的生产技术。专利涉及有意创造财产权利
Figure 12.2 Absolute cost advantage as a barrier to entry 图 12.2 绝对成本优势作为进入壁垒
new knowledge, intended to protect an innovator from imitation by rivals. From a public policy perspective, the motive for allowing patents may be to increase consumer welfare. Patents encourage firms to invest in research and development, with the promise of monopoly profits for successful innovators, as well as increased choice and utility for consumers. 新知识，旨在保护创新者免受竞争对手的模仿。从公共政策的角度来看，允许专利的动机可能是为了增加消费者福祉。专利鼓励企业投资于研究和开发，成功创新者有垄断利润的承诺，同时也增加了消费者的选择和效用。
However, patenting can also be used by an incumbent strategically, in an attempt to deter entry. For example, a firm in possession of a new technology may apply for multiple patents to cover all possible spin-offs, so as to deny rivals the opportunity to invent around the new technology. In chemicals, for example, minor variations in molecular structure can easily lead to the creation of new product spin-offs (Needham, 1976). In the defence industry, new firms incur substantial entry costs related to technology and research and development expenditure in order to produce sophisticated defence equipment (Hartley, 2003). Langinier (2004) presents a theoretical model that assesses the extent to which patents and patent renewals act as a barrier to entry. In cases of low demand and asymmetric information regarding market demand, patent renewal is shown to deter entry. However, if market demand is high, patent renewals do not discourage entry. The economics of patenting is examined in more detail in Section 18.5 . 然而，专利也可以被现有企业战略性地使用，试图阻止其他企业进入市场。例如，拥有新技术的公司可能申请多项专利以覆盖所有可能的衍生产品，从而阻止竞争对手绕过新技术进行发明。例如，在化学领域，分子结构的微小变化很容易导致新产品的衍生品的产生（Needham，1976）。在国防工业中，新公司需要承担与技术和研发支出相关的巨大进入成本，以生产复杂的国防装备（Hartley，2003）。Langinier（2004）提出了一个理论模型，评估专利和专利续展在阻碍市场进入方面的作用程度。在需求低且市场需求信息不对称的情况下，专利续展被证明可以阻止市场进入。然而，如果市场需求高，专利续展不会阻止市场进入。专利的经济学细节将在第 18.5 节中更详细地讨论。
Second, incumbent firms may have exclusive ownership of factor inputs. They may control the best raw materials, or have recruited the most qualified or experienced labour or management personnel. Consequently, entrants are forced to rely on more expensive, less-efficient or lower-quality alternatives. For example, British Airways exercises influence over landing slots at London's Heathrow Airport, forcing competitors to use less-attractive airports. However, through a variety of innovative strategies low-cost entrants have been able to overcome this entry barrier and operate profitably. For example, low-cost airlines have: unbundled their core product by charging separate prices for the flight itself and extras such as meals; reduced costs by using cheaper airports; simplified ticket purchase and check-in arrangements; reduced airport turnaround times; and made more intensive use of their aircraft (Johnson, 2003). 其次，现有企业可能拥有对要素输入的独家所有权。他们可能控制着最好的原材料，或者招募了最合格或经验丰富的劳动力或管理人员。因此，新进入者被迫依赖更昂贵、效率更低或质量更低的替代品。例如，英国航空公司对伦敦希思罗机场的降落时段具有影响力，迫使竞争对手使用不那么具吸引力的机场。然而，通过各种创新策略，低成本的新进入者已经能够克服这一进入壁垒并实现盈利。例如，低成本航空公司已经：通过为飞行本身和额外服务（如餐食）收取分开的价格来拆分其核心产品；通过使用更便宜的机场降低成本；简化购票和办理登机手续的安排；缩短机场周转时间；并更加密集地利用他们的飞机（约翰逊，2003）。
Third, incumbents may have access to cheaper sources of finance, if they are viewed by capital markets as less risky than new firms. For example, in pharmaceuticals, large incumbents with well-established research and development programmes are deemed less likely than their smaller counterparts to develop products that subsequently go on to fail drug trials. Lower risk means that preferential financial backing is easier to attain (Nightingale, 2003). If the new firm's management is previously unknown, any funds loaned are likely to carry a risk premium. 第三，如果资本市场认为现有企业比新企业风险较低，那么现有企业可能会获得更便宜的融资来源。例如，在制药业中，拥有成熟的研发计划的大型现有企业被认为比规模较小的竞争对手更不可能开发后来在药物试验中失败的产品。较低的风险意味着更容易获得优先的财务支持（Nightingale，2003）。如果新企业的管理层以前不为人知，那么借出的任何资金可能会带有风险溢价。
Finally, the presence of vertically integrated incumbents in industries such as biotechnology, brewing, iron, mobile telephones, steel or chemicals may force an entrant to operate at more than one stage of production if it wishes to overcome the incumbents' absolute cost advantage. In European brewing, for example, any new firm would not only manufacture beer, but also be able to source supplies, promote the finished product and establish an efficient network of distribution outlets (Lawler and Lee, 2003). Denying rivals access to inputs or markets through various forms of vertical exclusion may be subject to legal challenge under competition law (see Chapter 24), but this is not to say that such practices never take place. 最后，生物技术、酿造、铁路、移动电话、钢铁或化工等行业中垂直一体化的现有企业的存在可能会迫使新进入者在生产的多个阶段进行操作，以克服现有企业的绝对成本优势。例如，在欧洲的酿酒业中，任何新公司不仅需要生产啤酒，还需要能够采购原料、推广成品并建立高效的分销网络（Lawler 和 Lee，2003）。通过各种形式的垂直排斥拒绝竞争对手获取输入或市场的做法可能会受到竞争法律的法律挑战（参见第 24 章），但这并不意味着这种做法从未发生。
It is worth noting that an absolute cost differential need not always work in favour of the incumbent. It is possible that an incumbent has overpaid for its assets, in which case the entrant may be favoured. This might be true in industries reliant on rapidly changing technologies, such as computer hardware or software, whose costs fall rapidly over time. In some cases the entrant may be spared the costs of persuading consumers to accept a new idea or a new product, such costs having already been incurred by incumbents. 值得注意的是，绝对成本差异并不总是对现有企业有利。现有企业可能已经为其资产支付过高，这种情况下，新进入者可能会受益。在依赖快速变化技术的行业中，如计算机硬件或软件，成本会随时间迅速下降。在某些情况下，新进入者可能免受说服消费者接受新想法或新产品的成本，因为这些成本已经由现有企业承担过。
Demsetz (1982) argues that Bain's (1956) absolute cost advantage does not reflect the abuse of market power by incumbents, but simply reflects the scarcity of resources and the associated rents. However, this comment does not invalidate the preceding discussion, in so far as it concerns structural barriers to entry. These additional costs are real enough to potential entrants, and they do not necessarily derive from the exploitation of market power. Demsetz（1982 年）认为，Bain（1956 年）的绝对成本优势并不反映现有企业滥用市场权力，而只是反映资源稀缺和相关租金。然而，这一评论并没有否定前面的讨论，因为它涉及到进入的结构性障碍。这些额外成本对潜在的新进入者来说是真实存在的，并且它们不一定源于市场权力的利用。
Product differentiation 产品差异化
A barrier to entry exists if customers are loyal to the established brands and reputations of incumbents. A successful entrant will need to persuade customers to switch from their existing suppliers. This might be achieved either by selling the same product at a lower price, or launching advertising, marketing or other promotional campaigns (Comanor and Wilson, 1967). Due to price-cutting or increased costs (or both) the entrant is faced with a squeeze on profit, at least during the initial start-up phase. Product differentiation entry barriers include the following: 如果客户忠于现有品牌和现有企业的声誉，则存在进入壁垒。成功的新进入者将需要说服客户从现有供应商那里转投。这可能通过以更低的价格销售相同的产品，或者推出广告、营销或其他促销活动来实现（Comanor 和 Wilson，1967）。由于降价或成本增加（或两者兼有），新进入者在至少初创阶段面临利润挤压。产品差异化进入壁垒包括以下内容：
High advertising imposes additional costs upon entrants. To overcome existing brand loyalties or customer inertia, the entrant must spend proportionately more on advertising for each prospective customer. This is an absolute cost advantage barrier. For example, in the brewing industry it is estimated that the 高额广告费用给新进入者带来额外成本。为了克服现有品牌忠诚度或客户惰性，新进入者必须为每位潜在客户投入更多广告费用。这是绝对成本优势壁垒。例如，在酿酒行业，据估计，通过广告建立一个领先的欧洲品牌需要大约 20 年（Competition Commission，2001；Lawler 和 Lee，2003）。
establishment of a leading European brand through advertising takes around 20 years (Competition Commission, 2001; Lawler and Lee, 2003).
If entry takes place on a small scale, the entrant will not benefit from economies of scale in advertising. Large-scale advertisers may benefit from an increasingly effective message, and decreasing average advertising costs. 如果参与者规模较小，则参与者将无法从广告规模经济中受益。大规模广告商可能会从日益有效的信息和降低的平均广告成本中受益。
The funds needed to finance an advertising campaign may incur a risk premium, as this type of investment is high risk. Furthermore, it creates no tangible assets that can be sold in the event of failure. 用于资助广告活动所需的资金可能会带来风险溢价，因为这种投资属于高风险。此外，它不会创造任何可以在失败时出售的有形资产。
In some cases, incumbents may deliberately seek to increase the degree of product differentiation through brand proliferation, in order to raise barriers to entry. Product differentiation or brand proliferation as a form of entry-deterring strategy is examined in Section 12.3. 在某些情况下，现有企业可能会故意通过品牌扩张来增加产品差异化程度，以提高准入壁垒。产品差异化或品牌扩张作为一种阻止进入的策略在第 12.3 节中进行了探讨。
Switching costs 转换成本
Switching costs are incurred when customers face additional costs if they decide to change the supplier of a product or service. Switching costs may include: search costs incurred in acquiring information about alternative products or services; the costs of learning how to use a different product or service; and installation or disconnection charges. Switching costs raise barriers to entry into markets for a wide range of products such as credit cards, computer software, utilities (supplies of gas, electricity and water), telephones and banking services. 当客户决定更换产品或服务的供应商时，会产生转换成本。转换成本可能包括：获取有关替代产品或服务信息而产生的搜索成本；学习如何使用不同产品或服务的成本；以及安装或断开连接的费用。转换成本提高了进入市场的壁垒，适用于各种产品，如信用卡、计算机软件、公用事业（燃气、电力和水的供应）、电话和银行服务。
For example, consumers wishing to change a mobile telephone may have to purchase a new handset, master a new interface, pay a disconnection charge, and set up new billing arrangements. Further switching costs may be incurred when a good or service is tied to an aftermarket, through servicing or the need to purchase refills or replacement components. Tying makes it difficult for users to switch to alternative suppliers. Users become locked in to an existing supplier, which acquires ex post market power. Bargain-then-ripoff pricing, a policy of offering new customers a low price to attract their custom and then charging existing customers a high price in order to extract increased revenue or profit, works best when locked in customers can be separated from new ones; for example, in markets where users are tied into buying complementary products, such as ink refills or spare parts for cars; or in markets where prices are individually negotiated. If there is only one price, the supplier must compromise between a low price to attract new users and a high price to exploit locked-in users. 例如，希望更换手机的消费者可能需要购买新手机、掌握新界面、支付解约费用，并建立新的计费安排。当商品或服务与售后市场相关联时，可能会产生进一步的切换成本，例如维修或购买补充或更换零部件的需求。捆绑销售使用户难以转向其他供应商。用户被锁定在现有供应商那里，后来获得市场权力。先让利后宰客的定价策略，即向新客户提供低价以吸引他们，然后向现有客户收取高价以获取增加的收入或利润，在锁定客户可以与新客户分开的情况下效果最好；例如，在用户被迫购买配套产品的市场，如墨盒或汽车备件；或在价格是单独协商的市场。如果只有一个价格，供应商必须在吸引新用户的低价和剥削锁定用户的高价之间取得折衷。
To what extent do switching costs distort competition? Barriers to entry arising from switching costs due to incompatibility of technological standards can result in the segmentation of a market into submarkets or segments, such that an incumbent within a particular segment concentrates on charging high prices to its existing customers, and does not even attempt to attract customers from rival producers. Klemperer (2008) suggests that in view of the anticompetitive and entry-deterring effects of switching costs, regulatory attention should focus 切换成本到底会对竞争产生何种程度的扭曲？由于技术标准不兼容而产生的切换成本所带来的进入壁垒可能导致市场分割成子市场或细分市场，以至于特定细分市场内的现有企业专注于向现有客户收取高价，甚至不会尝试吸引来自竞争对手的客户。克莱姆佩勒（2008）指出，鉴于切换成本的反竞争和阻止进入的影响，监管注意力应集中在那些不兼容性是战略选择而非技术性质所决定的情况上。
on situations where incompatibility is a matter of strategic choice rather than governed by the nature of the technology. 在网络外部性
Network externalities arise when the value of a product or service to a consumer depends upon the number of other consumers using the same product or service (Katz and Shapiro, 1985; Economides, 1996; Farrell and Klemperer, 2007; Klemperer, 2008). Each consumer purchases the product or service for their own benefit, but by doing so they (unintentionally) create a benefit for other users who gain extra value as the size or coverage of the network of users increases. Network externalities make it difficult for new firms to enter when an incumbent has already established a large or comprehensive user network. As more users buy into the network, an effective monopoly might be created, raising formidable barriers to entry for any entrant wishing to challenge the dominance of the established product, service or technological standard. Chapter 22 examines the economics of markets that are subject to network externalities. 网络外部性是指产品或服务对消费者的价值取决于使用相同产品或服务的其他消费者数量时产生的现象（Katz 和 Shapiro，1985 年；Economides，1996 年；Farrell 和 Klemperer，2007 年；Klemperer，2008 年）。每个消费者购买产品或服务是为了自己的利益，但这样做会（无意中）为其他用户创造价值，随着用户网络的规模或覆盖范围增加，其他用户会获得额外的价值。网络外部性使得新公司很难进入市场，当现有公司已经建立了庞大或全面的用户网络时。随着更多用户加入网络，可能会形成有效的垄断，为任何希望挑战已建立产品、服务或技术标准的主导地位的新进入者设立难以逾越的准入壁垒。第 22 章探讨了受网络外部性影响的市场的经济学。
Markets subject to network externalities include those in which users are linked through communication systems such as telephones or the internet. Computer operating systems and widely used applications, such as Microsoft Windows and Microsoft Office, are subject to network externalities. For example, the value to a jobseeker of acquiring the skills required to use Microsoft products increases with the number of employers that use the same products. The ability to share files that are specific to Microsoft products depends on the number of other users of the same products. Stock and derivatives exchanges are also subject to network externalities. As the number of traders in an established exchange increases, liquidity increases and transaction costs decrease. A new exchange might face a formidable barrier to entry in attempting to overcome these advantages. 市场受网络外部性影响的范围包括那些用户通过通信系统（如电话或互联网）相互联系的市场。计算机操作系统和广泛使用的应用程序，如微软 Windows 和微软 Office，都受到网络外部性的影响。例如，对于求职者来说，获得使用微软产品所需技能的价值会随着使用相同产品的雇主数量的增加而增加。分享特定于微软产品的文件的能力取决于使用相同产品的其他用户数量。股票和衍生品交易所也受到网络外部性的影响。随着已建立交易所中交易者数量的增加，流动性增加，交易成本降低。新交易所可能面临巨大的进入壁垒，试图克服这些优势。
Direct network externalities exist when the network becomes more attractive to new users as the level of adoption increases. Indirect network externalities arise when increased adoption affects a related market. Bandwagon effects are characteristic of successful networks. Success in establishing a network depends on users' expectations as to which network will achieve dominance, and on the coordination of users' choices. In the early stages of the commercial development of a new technological standard, producers tend to compete aggressively, knowing that success depends not only on the tastes of individual consumers, but also on their expectations as to the most likely winner. 直接网络外部性存在于当网络的采用水平增加时，网络对新用户变得更具吸引力。间接网络外部性是指增加采用对相关市场产生影响。成功网络的特征是随波逐流效应。建立网络的成功取决于用户对哪个网络将取得主导地位的期望，以及用户选择的协调。在新技术标准的商业发展的早期阶段，生产者往往会进行激烈竞争，因为他们知道成功不仅取决于个体消费者的品味，还取决于他们对最有可能获胜者的期望。
With compatible technological standards, consumers may be able to enjoy full network benefits without having to buy from a single producer. If consumers are willing to pay a higher price for this benefit, then firms might be encouraged to supply compatible products. However, an incumbent might still prefer incompatibility, because this serves as a barrier to entry. Incompatibility might damage consumers in several ways. Competing standards may result in market fragmentation, in which case the benefits of network externalities fail to materialise. On the other hand, if the market 'tips' towards one technological standard, 有了兼容的技术标准，消费者可能能够享受到完整的网络效益，而无需从单一生产商购买。如果消费者愿意为此付出更高的价格，那么企业可能会被鼓励提供兼容的产品。然而，现有企业可能仍然更喜欢不兼容性，因为这可以作为进入市场的障碍。不兼容性可能以多种方式损害消费者。竞争标准可能导致市场碎片化，这种情况下网络外部性的好处无法实现。另一方面，如果市场向一个技术标准“倾斜”，
it is possible that a later and technologically superior standard fails to become established. Competition between producers seeking to become the established standard might encourage bargain-then-ripoff pricing. Producers may initially compete aggressively in order to become the standard, but the winner may subsequently abuse its market power so as to earn abnormal profits (Salop and Stiglitz, 1977). 可能会导致后来的技术上更先进的标准无法确立。生产商之间为成为确立标准而进行的竞争可能会鼓励讨价还价然后剥削定价。生产商可能最初会积极竞争以成为标准，但获胜者随后可能会滥用其市场权力以赚取异常利润（Salop 和 Stiglitz，1977）。
Legal barriers to entry 进入市场的法律障碍
Legal barriers to entry are erected by governments and enforced by law. Both the Chicago and Austrian schools view legal barriers as highly damaging to competition. Examples of legal barriers include the following: 政府设立并依法执行法律壁垒。芝加哥学派和奥地利学派都认为法律壁垒对竞争具有极大破坏性。法律壁垒的例子包括以下内容：
Registration, certification and licensing of businesses and products. Some industries are characterised by the need to seek official permission to trade, for example pubs, taxis, airlines and defence equipment (Hartley, 2003). For pharmaceuticals, legal barriers to entry facing new firms or products are high, arising from the framework of safety rules and regulations requiring products to satisfy a myriad of standards and tests (Nightingale, 2003). In some cases, incumbents may press for more stringent regulation, in an attempt to keep out firms that do not meet industry standards. Under this guise of maintaining standards, low-cost entrants may be denied access to the market. 企业和产品的注册、认证和许可。有些行业需要寻求官方许可才能交易，例如酒吧、出租车、航空公司和国防装备（Hartley，2003 年）。对于制药业，新公司或产品面临的法律壁垒很高，源于安全规则和法规框架要求产品满足多种标准和测试（Nightingale，2003 年）。在某些情况下，现有企业可能会要求更严格的监管，试图阻止不符合行业标准的公司进入市场。在维护标准的幌子下，低成本的新进入者可能被拒绝进入市场。
Monopoly rights. Monopoly rights may be granted by legislation. The government might allow certain firms exclusive rights to produce certain goods and services for a limited or unlimited period. An example is franchised monopolies in industries such as the railways, mobile telephones and television broadcasting. Franchised monopolies are often awarded in situations of natural monopoly, where average costs are minimised when one firm occupies the entire market, or in cases where firms require the guarantee of a relatively large market share in order to invest in technology and product development. 垄断权利。垄断权利可能由立法授予。政府可能允许某些公司在有限或无限期内独家生产某些商品和服务。一个例子是在铁路、移动电话和电视广播等行业中的特许经营垄断。特许经营垄断通常在自然垄断的情况下授予，即当一家公司占据整个市场时，平均成本最低，或者在公司需要保证相对较大的市场份额以便投资于技术和产品开发的情况下。
Patents. As noted above, patenting involves the deliberate creation of a property right, enforced by law. Ownership of a patent confers monopoly rights and the potential to earn an abnormal profit, usually for a fixed period. The intention is to encourage research and development and innovation, by enabling successful innovators to appropriate the returns from their original investment. The disadvantage, from a public policy perspective, is that by granting an incumbent exclusive rights to use a piece of technology or produce a particular product, competition is impeded and the pace of diffusion of a technology is inhibited. 专利。如上所述，专利涉及有意创造一项财产权利，并受法律保护。拥有专利赋予了垄断权利和赚取异常利润的潜力，通常为一定期限。其目的是通过使成功的创新者能够收回其最初投资的回报，从而鼓励研究和开发以及创新。从公共政策的角度来看，缺点是通过授予现有企业对某项技术的专有使用权或生产特定产品的专有权，会阻碍竞争，抑制技术扩散的速度。
Government policies. Government policies can also create legal barriers to entry directly. Friedman (1962) suggests tariffs, tax policies and employment laws may all impede entry, either directly or indirectly. For example, in several European countries car tax is related to engine capacity. This has the effect of increasing the price of cars imported from the US, which have greater engine capacity on average. 政府政策。政府政策也可以直接制造法律壁垒以阻碍进入。弗里德曼（1962 年）认为关税、税收政策和就业法律都可能直接或间接地阻碍进入。例如，在几个欧洲国家，汽车税与发动机排量有关。这导致了从美国进口的汽车价格上涨，因为这些汽车的平均发动机排量更大。
Klapper et al. (2004) examine ways in which regulation hampers entry, especially in industries where start-up costs are low and high rates of entry would Klapper 等人（2004 年）研究了监管如何阻碍进入，特别是在创业成本低且进入率高的行业。
normally be expected. Value added in naturally 'high-entry' industries tends to grow more slowly in countries with high entry barriers. 通常可以预期的。在自然“高准入”行业中增加的价值在准入壁垒较高的国家往往增长较慢。
Geographic barriers to entry 地理准入壁垒
Geographic barriers to entry include restrictions faced by foreign firms attempting to trade in the domestic market. Geographic barriers affect the extent and type of entry (for example, greenfield investments, acquisitions or joint ventures) undertaken by foreign firms (Elango and Sambharya, 2004). Examples of geographic entry barriers include the following: 地理准入壁垒包括外国企业在国内市场进行贸易时面临的限制。地理准入壁垒影响外国企业进行的准入程度和类型（例如，绿地投资、收购或合资）（Elango 和 Sambharya，2004 年）。地理准入壁垒的示例包括以下内容：
Physical barriers. Frontier controls and customs formalities create administrative and storage costs, and lead to delays in transactions being completed. 物理障碍。边境管制和海关手续会产生行政和存储成本，并导致交易完成时出现延迟。
Technical barriers. Technical barriers include requirements to meet specific technical standards, employment regulations, health and safety regulations and transport regulations. 技术障碍。技术障碍包括满足特定技术标准、就业法规、卫生和安全法规以及运输法规的要求。
Fiscal barriers. Aspects of a country's fiscal regime may disadvantage foreign firms. Exchange controls may impose costs on foreign firms that need to convert currencies in order to trade. Tariffs, quotas or subsidies to domestic producers may place foreign producers at a disadvantage relative to domestic producers. 财政障碍。一个国家财政制度的某些方面可能会对外国企业造成不利影响。外汇管制可能会对需要兑换货币进行贸易的外国企业造成成本。关税、配额或对国内生产者的补贴可能会使外国生产者相对于国内生产者处于不利地位。
Preferential public procurement policies. Purchasing policies practised by national governments may give preferential treatment to domestic firms, placing foreign competitors at a disadvantage. 优惠的政府采购政策。国家政府实施的采购政策可能会偏向国内企业，使外国竞争对手处于不利地位。
Language and cultural barriers. Language or other cultural differences between countries may also be considered as a geographic barrier to entry (Ghemawat, 2003). 语言和文化障碍。国家之间的语言或其他文化差异也可能被视为进入的地理障碍（Ghemawat，2003）。
Case study 12.1 案例研究 12.1
Barriers to entry in retail banking 零售银行业准入壁垒
New entrants to the retail banking sector face significant challenges in attracting customers and expanding their market shares, an OFT review has found. The review of barriers to entry, expansion and exit in retail banking was launched in May 2010 to identify any obstacles blocking firms from entering the sector or from successfully competing against existing firms, as well as factors preventing inefficient firms from exiting the market and being replaced by more efficient ones. 零售银行业的新进入者面临着吸引客户和扩大市场份额方面的重大挑战，一项 OFT 审查发现。 2010 年 5 月启动了对零售银行业准入、扩张和退出壁垒的审查，以确定任何阻碍公司进入该行业或成功与现有公司竞争的障碍，以及阻止低效公司退出市场并被更高效公司取代的因素。
The OFT has established a body of evidence relating to the size and significance of potential barriers, based on extensive consultation with the industry, including established incumbent banks and building societies, new and prospective entrants and consumer and industry groups. A copy of the review will be submitted to the Independent Commission on Banking which is examining issues of competition and stability in the banking market. OFT 已经建立了一系列与潜在壁垒的规模和重要性相关的证据，这些证据是基于与行业的广泛磋商而得出的，包括已建立的现有银行和建筑协会、新的和潜在的进入者以及消费者和行业团体。审查报告的副本将提交给正在审查银行市场竞争和稳定性问题的独立银行委员会。
The OFT examined four aspects of personal and small and medium-sized enterprise (SME) banking to identify possible barriers: 1 . the regulatory process; 2 . access to essential inputs necessary to offer retail banking products such as IT systems, payment schemes, information and finance; 3 . the ability of new entrants to grow by attracting new customers; 4 . issues around exiting the market. 英国公平贸易办公室（OFT）审查了个人和中小企业（SME）银行业的四个方面，以确定可能存在的障碍：1.监管流程；2.获取提供零售银行产品所需的基本输入的途径，如 IT 系统、支付方案、信息和金融；3.新进入者通过吸引新客户实现增长的能力；4.退出市场的问题。
While the review found that most prospective entrants are able to meet regulatory requirements, and source the necessary inputs to offer retail banking services, new providers face difficulties in attracting customers and expanding market share. This is because of the reluctance of personal and small business customers to switch providers, their loyalty to established brands, and preference for banks with a local branch. This was most marked for personal and business current account customers, whereas personal customers were more likely to shop around for loan products. 尽管审查发现大多数潜在的新进入者能够满足监管要求，并获取提供零售银行服务所需的输入，但新提供者在吸引客户和扩大市场份额方面面临困难。这是因为个人和小型企业客户不愿意更换供应商，他们忠诚于已建立的品牌，并偏爱设有本地分支机构的银行。这在个人和企业活期账户客户中最为明显，而个人客户更有可能为贷款产品四处比价。
The other major findings were that: 其他主要发现是：
Some firms reported problems around the process of becoming authorised by the FSA to accept deposits, with a lack of transparency and uncertainty causing delays and difficulties in raising funds. The FSA has recently revised its authorisation process and this should lead to greater transparency and certainty. 一些公司报告称，在成为 FSA 授权接受存款的过程中出现了问题，缺乏透明度和不确定性导致了筹集资金的延迟和困难。 FSA 最近修订了其授权流程，这应该会带来更大的透明度和确定性。
Existing capital requirements may disproportionately affect new entrants and smaller banks by requiring them to hold proportionally more capital than incumbents. As capital and liquidity requirements are updated, it may be appropriate for the prudential regulators to consider and monitor their impact on competition. 现有的资本要求可能会对新进入者和较小的银行产生不成比例的影响，因为它们被要求持有的资本比现有银行更多。 随着资本和流动性要求的更新，审慎监管机构可能需要考虑和监测其对竞争的影响。
Entering the market involves significant IT investment, often in the form of sunk costs, which can account for up to two-thirds of start-up costs. This makes it all the more important for firms to be able to grow quickly, to spread those costs over a larger customer base. 进入市场需要进行重大的 IT 投资，通常以沉没成本的形式出现，这可能占创业成本的三分之二。 这使得公司更加重要的是能够快速增长，将这些成本分摊到更大的客户群体上。
New entrants are able to access industry-wide payment schemes such as CHAPS and BACS, and information on personal and SME customer risk profiles is widely available. However, credit risk information about micro-enterprises is limited, which may make it harder for new banks to lend to the smallest firms. 新进入者可以访问诸如 CHAPS 和 BACS 之类的全行业支付方案，并且个人和中小企业客户风险概况的信息是广泛可得的。然而，有关微型企业的信用风险信息有限，这可能会使新银行更难向最小的公司提供贷款。
Following the financial crisis, the ability of some firms to expand could be constrained by the current lack of interbank lending. 在金融危机之后，一些公司扩张的能力可能会受到当前缺乏银行间贷款的限制。
There is no evidence to suggest that the regulatory framework dealing with how a failing bank exits the sector prevents inefficient firms leaving the market, but the OFT encourages the authorities to give due consideration to competition issues when these arrangements are operated. 没有证据表明处理失败银行退出该行业的监管框架会阻止低效公司退出市场，但 OFT 鼓励当局在运作这些安排时充分考虑竞争问题。
The review also explored whether there are specific issues around barriers to entry, expansion and exit in England, Scotland, Northern Ireland and Wales. While the review did not find significant differences in relation to most of the themes covered, it did find that brand loyalty to incumbent national brands in Scotland and Northern Ireland may 该审查还探讨了在英格兰、苏格兰、北爱尔兰和威尔士的进入、扩张和退出障碍是否存在特定问题。虽然审查并未发现与大多数涉及主题相关的显著差异，但发现苏格兰和北爱尔兰对现有国家品牌的品牌忠诚度可能比英国其他地方更高，并且新进入者选择位置主要受潜在客户群规模的影响，高度人口稠密的城市地区被视为比农村地区更具吸引力。
be greater than elsewhere in the UK and that new entrants' choice of location is largely driven by the size of the potential customer base, with highly populated urban areas seen as more attractive than rural areas. Clive Maxwell，OFT 商品、服务和合并执行董事表示：
Clive Maxwell, OFT Executive Director for Goods, Services and Mergers said:
Vigorous competition in retail banking is vital for personal and small business customers and helps support growth and productivity in the economy. If firms face significant difficulties in entering and competing in the market, incumbents have less incentive to reduce costs, innovate and price competitively. 零售银行业中的激烈竞争对个人和小型企业客户至关重要，并有助于支持经济增长和生产力。如果公司在进入和竞争市场方面面临重大困难，现有企业就缺乏降低成本、创新和具有竞争力定价的动力。
A number of firms have recently entered the market, and more are expected to follow. While we found few barriers to setting up, new firms trying to grow in this market face difficulties due to customers' low levels of switching, loyalty to incumbent providers, and attachment to a local branch. 最近有许多公司进入了市场，预计会有更多公司跟进。尽管我们发现设立障碍不多，但试图在这个市场中发展壁垒的新公司面临困难，因为客户很少更换服务提供商、忠诚于现有提供商并依恋当地分支机构。
We hope that this review will be of value to the Independent Commission on Banking, and contribute to the wider debate on the future of banking. 我们希望这份审查能对独立银行委员会有价值，并为关于银行业未来的广泛讨论做出贡献。
As a result of the above OFT report, the FSA (Financial Services Authority) was given the task of examining whether its regulatory framework was too 'burdensome' for new entrants. In 2013 FSA issued a review of its processes and rules, and described changes that would facilitate easier market entry in future covering 'both the specific prudential, conduct and organizational requirements that must be put in place for authorisation, and the process through which these rules are applied. 由于上述 OFT 报告的结果，FSA（金融服务管理局）被赋予了审查其监管框架是否对新进入者来说过于“繁重”的任务。2013 年，FSA 发布了对其流程和规则的审查，并描述了将来将促进更容易进入市场的变化，涵盖了“必须为授权设立的特定审慎、行为和组织要求，以及这些规则适用的过程。
Sources: Office of Fair Trading (2010) Review of Barriers to Entry, Expansion and Exit in Retail Banking. London: HMSO. 来源：公平交易办公室（2010 年）《零售银行进入、扩张和退出障碍审查》。伦敦：HMSO。
Financial Services Authority (2013) A review of requirements for firms entering into or expanding in the banking sector. London: HMSO. 金融服务管理局（2013 年）《进入或扩张银行业的公司要求审查》。伦敦：HMSO。
Case study 12.2 案例研究 12.2
Competition watchdog focuses on bank account switching 竞争监管机构关注银行账户切换
Halfway through its investigation of retail banking, the UK competition watchdog has said barriers to entry are not a big problem and it is focusing on why customers are not switching current accounts. The Competition and Markets Authority has been formally reviewing personal current accounts and small business lending since November, looking at whether a few big banks have too large a share of the market, at barriers for new lenders and at the ability of customers to switch accounts. It said on Thursday it will consider 在对零售银行业进行调查的过程中，英国竞争监管机构表示，进入市场的障碍并不是一个大问题，他们正在关注客户为何不切换活期账户。自去年 11 月以来，竞争与市场管理局一直在正式审查个人活期账户和小额企业贷款，研究少数几家大银行是否在市场上占有过大份额，新贷款人面临的障碍以及客户切换账户的能力。该机构周四表示，将考虑
whether the fact that customers may have a number of services from the same bank-such as loans, credit cards and overdrafts - 'might make switching more difficult, and whether activities such as cross-selling of products and tying or bundling of banking products occurs and may increase switching costs and act as a barrier to entry and expansion'. 顾客可能从同一家银行获得多种服务，如贷款、信用卡和透支，这可能会使换银行更加困难，以及交叉销售产品、捆绑银行产品等活动是否发生，可能会增加换银行的成本，并作为进入和扩张的障碍。
Its initial findings indicate there is not a significant problem with barriers to entering the market. Banks have been opening or expanding in the UK: Santander and Metro Bank have seen the biggest increase in market share for current accounts since 2011, while Nationwide and TSB have seen small increases, the CMA said. The combined market share of the four largest banks-Lloyds Banking Group, Royal Bank of Scotland, Barclays and HSBC - has been decreasing, though they still account for more than 70 per cent. 初步调查结果表明，进入市场的障碍并不是一个重大问题。英国的银行一直在开设或扩张业务：根据 CMA 的说法，自 2011 年以来，桑坦德银行和大都会银行的市场份额在活期账户方面增长最多，而全国银行和 TSB 的市场份额增长较小。四大银行（劳埃德银行集团、苏格兰皇家银行、巴克莱银行和汇丰银行）的综合市场份额一直在减少，尽管它们仍占据了 70%以上的市场份额。
The CMA research indicates a bigger problem may be that retail customers tend not to switch banks. In a survey by the watchdog, about 3 per cent of customers said they switched their main current account in the past year but 81 per cent did not even look at different options. While about half said they did not look for another account because they were 'very satisfied' with their provider, the regulator expressed worry that this is because they have low expectations. CMA 的研究表明，更大的问题可能是零售客户往往不会更换银行。在监管机构进行的一项调查中，约有 3%的客户表示他们在过去一年里更换了他们的主要活期账户，但 81%的客户甚至没有考虑过不同的选择。大约一半的人表示他们没有寻找其他账户是因为他们对自己的服务商“非常满意”，但监管机构担心这是因为他们期望值较低。
The CMA said it had not reached any conclusions on the subject and would continue to focus on customer perceptions of switching, and whether having multiple products from the same bank makes it harder to move. Paul Pester, chief executive of TSB, said the UK banking market was not working 'for the real benefit of UK consumers'. 'Creating a more dynamic switching market, addressing the scale advantages of the big banks and tackling barriers to entry can help consumers get a better deal and ultimately rebuild trust in the industry,' he said. The CMA has also hired Deloitte, a consultancy, to research new products and services in retail banking and what they mean for competition. The review also found a shortage of customer information about the quality of bank service and the cost of overdrafts. 英国竞争与市场管理局表示，他们尚未就该主题达成任何结论，将继续关注客户对转换的看法，以及同一银行拥有多种产品是否会增加转换难度。TSB 首席执行官保罗·佩斯特表示，英国银行市场并未为英国消费者的真正利益而运作。他说：“打造更具活力的转换市场，解决大银行的规模优势问题，以及消除进入壁垒，可以帮助消费者获得更好的交易，并最终重建对该行业的信任。”竞争与市场管理局还聘请了咨询公司德勤，研究零售银行业的新产品和服务以及它们对竞争的影响。审查还发现客户缺乏有关银行服务质量和透支费用的信息。
Alex Chisholm, chief executive of the CMA, told the Financial Times in November that it was also investigating free banking for customers whose current accounts are in credit. The regulator has the power to demand that companies divest parts of their business or change the prices of their products. It can also demand changes to the way banks provide information to customers and impose price changes. CMA 首席执行官亚历克斯·奇索姆（Alex Chisholm）在 11 月告诉《金融时报》，CMA 还在调查对那些活期账户处于信用状态的客户提供免费银行服务。监管机构有权要求公司剥离业务部分或调整产品价格。它还可以要求银行改变向客户提供信息的方式并实施价格调整。
Abridged 简化版
Source: FT May 21,2015 Lindsay Fortado 来源：FT 2015 年 5 月 21 日 Lindsay Fortado
Bain (1956) argues that barriers to entry arising from economies of scale, absolute cost advantage and product differentiation are generally stable in the long run. However, this does not imply these barriers should be regarded as permanent. The same comment applies to entry barriers arising from switching costs and network externalities, and legal and geographic barriers. Market structures can and do change eventually, and the importance of any entry barrier can vary Bain（1956）认为，由规模经济、绝对成本优势和产品差异化引起的准入壁垒在长期内通常是稳定的。然而，这并不意味着这些壁垒应被视为永久性的。同样的评论也适用于由转换成本和网络外部性、法律和地理壁垒引起的准入壁垒。市场结构最终可以发生变化，任何准入壁垒的重要性也可能随时间而变化。
over time. For example, new technology may reshape the LRAC functions of both incumbents and entrants, transforming the nature of economies of scale. New deposits of a raw material may be discovered, reducing the absolute cost advantage enjoyed by an incumbent. One highly innovative marketing campaign might completely wipe out long-established brand loyalties or other product differentiation advantages of incumbents. 例如，新技术可能重塑现有企业和新进入者的 LRAC 函数，改变规模经济的性质。可能会发现新的原材料储量，降低现有企业享有的绝对成本优势。一项高度创新的营销活动可能会完全消灭长期建立的品牌忠诚度或其他现有企业的产品差异化优势。
The Chicago school regards Bain's definition of barriers to entry, which includes any obstacle a new firm must overcome to enter a market, as too general to be useful. Stigler's preferred definition is limited to factors that impose a higher long-run production cost on the entrant than on the incumbent. The Chicago school argues that it is rare for such a cost differential to endure in the long run. Therefore the most important issue is not the existence of barriers to entry, but rather the speed with which entry barriers can be surmounted (Stigler, 1968; Demsetz, 1982). 芝加哥学派认为，贝恩对于进入壁垒的定义包括任何新公司必须克服的障碍，过于笼统而无用。斯蒂格勒更倾向于将其定义限制在那些对新进入者施加比现有公司更高的长期生产成本的因素上。芝加哥学派认为，在长期内，很少有这种成本差异会持续存在。因此，最重要的问题不是存在进入壁垒，而是进入壁垒可以被克服的速度（斯蒂格勒，1968 年；戴姆塞茨，1982 年）。
12.3 Entry-deterring strate 12.3 进入阻挡策略
The barriers to entry examined in Section 12.2 stem from underlying product or technological characteristics, and cannot be changed easily by incumbent firms. In contrast, entry-deterring strategies are barriers to entry that are created or raised deliberately by incumbents through their own actions. Relevant actions might include changes in price or production levels, or in some cases merely the threat that such changes will be implemented if entry takes place. A credible threat of this kind may be sufficient to deter potential entrants from proceeding. The extent to which it is possible for an incumbent to adopt entry-deterring strategies depends on the degree of market power exercised by the incumbent (Cabral, 2008). 第 12.2 节中所检验的进入壁垒源于基础产品或技术特征，且不容易被现有企业改变。相比之下，阻止进入的策略是指那些由现有企业通过自身行动故意创造或提高的进入壁垒。相关行动可能包括价格或生产水平的变化，或在某些情况下仅仅是这样的变化将会被实施的威胁，如果有企业进入市场。这种可信的威胁可能足以阻止潜在的进入者继续前进。现有企业能够采取阻止进入的策略的程度取决于现有企业所行使的市场权力的程度（Cabral，2008）。
This section examines three types of entry-deterring strategy. The first two are pricing strategies: limit pricing and predatory pricing. The third is strategic product differentiation or brand proliferation, whereby incumbents employ advertising or other forms of marketing activity to strengthen brand loyalties. 本节探讨了三种类型的阻止进入策略。前两种是定价策略：限价和掠夺性定价。第三种是战略产品差异化或品牌扩张，即现有企业通过广告或其他形式的营销活动来加强品牌忠诚度。
Limit pricing 限价
Suppose a market is currently serviced by a single producer but entry barriers are not insurmountable. The incumbent therefore faces a threat of potential entry. According to the theory of limit pricing, the incumbent might attempt to prevent entry by charging a price, known as the limit price, defined as the highest price the incumbent believes it can charge without inviting entry. The limit price is below the monopoly price, but above the incumbent's average cost. Therefore the incumbent earns an abnormal profit, but this abnormal profit is lower than the monopoly profit (Martin, 2008). 假设市场目前由单一生产者提供服务，但进入壁垒并非不可逾越。因此，现任面临潜在进入的威胁。根据限价理论，现任可能会试图通过收取一种价格（称为限价）来阻止进入，限价被定义为现任认为自己可以收取的最高价格，而不会引发进入。限价低于垄断价格，但高于现任的平均成本。因此，现任赚取异常利润，但这种异常利润低于垄断利润（Martin，2008）。
To pursue a limit-pricing strategy, the incumbent must enjoy some form of cost advantage over the potential entrants. In the limit pricing models developed below, this is assumed to take the form of either an absolute cost advantage or an economies of scale entry barrier. It is therefore assumed that a structural barrier 要实施限价策略，现任必须在潜在进入者身上享有某种形式的成本优势。在下文中开发的限价模型中，假定这种优势采取绝对成本优势或规模经济的形式。因此，假定存在一种结构性壁垒
to entry exists, but this barrier may be surmountable unless the incumbent adopts a pricing strategy that makes it unattractive for entrants to proceed. 存在，但除非现任采取一种使得进入者不愿继续的定价策略，否则这种壁垒可能是可以克服的。
A critical assumption underlying models of limit pricing concerns the nature of the reaction the entrants expect from the incumbent, if the entrants proceed with their entry decision. A key assumption of these models is that entrants assume the incumbent would maintain its output at the pre-entry level in the event that entry takes place. Therefore the incumbent is prepared to allow price to fall to a level determined by the location of the combined post-entry output (of the incumbent and entrants) on the market demand function (Sylos-Labini, 1962). Notice that this assumption (which has been termed the Sylos Postulate in the barriers to entry literature) is equivalent to the zero conjectural variation assumption that we have encountered previously in the development of the Cournot duopoly model (see Section 7.3). 限价模型的一个关键假设涉及竞争对手对于现有企业的反应性质，如果竞争对手继续进行进入决策。这些模型的一个关键假设是，竞争对手假设现有企业会在进入发生时保持其产出在进入前的水平。因此，现有企业准备允许价格下降到由市场需求函数上的组合后进入产出（现有企业和竞争对手的产出）的位置决定的水平（Sylos-Labini，1962）。请注意，这个假设（在进入壁垒文献中被称为 Sylos 假设）等同于我们在 Cournot 双头垄断模型发展中之前遇到的零猜测变化假设（请参见第 7.3 节）。
Figure 12.3 shows the limit pricing model in the case of an absolute cost advantage entry barrier. It is assumed there is a single incumbent and a fringe comprising a large number of small competitive potential entrants. LRAC is the incumbent's average cost function, and is the entrants' average cost function. In order to concentrate solely on the effects of absolute cost advantage (and exclude economies of scale), it is assumed both LRAC functions are horizontal, and therefore equivalent to the long-run marginal cost (LRMC) functions. The incumbent's monopoly price and output are ( ). At all output levels, the entrants' average cost is below . Therefore, if the incumbent operates at ( ) initially, entry takes place subsequently. The entrants produce Q. , reducing the price to , and reducing the incumbent's abnormal profit from (pre-entry) to (post-entry). 图 12.3 显示了绝对成本优势进入壁垒情况下的限价模型。假设存在一个现有企业和一个由大量潜在的小型竞争对手组成的边缘市场。LRAC 是现有企业的平均成本函数， 是新进入者的平均成本函数。为了专注于绝对成本优势的影响（并排除规模经济），假设两个 LRAC 函数都是水平的，因此等同于长期边际成本（LRMC）函数。现有企业的垄断价格和产量为（ ）。在所有产量水平上，新进入者的平均成本都低于 。因此，如果现有企业最初以（ ）的产量运营，随后会发生进入。新进入者生产 Q. ，将价格降至 ，并将现有企业的异常利润从 （进入前）降至 （进入后）。
Suppose instead the incumbent pursues a limit-pricing strategy in the short run. This involves operating at initially. If entry takes place, industry 相反，假设现有企业在短期内采取限价策略。这涉及最初以 的产量运营。如果发生进入，行业
Figure 12.3 Limit pricing to deter entry: absolute cost advantage 图 12.3 限价以阻止进入：绝对成本优势
output is increased above , causing price to fall below . The entrants' residual demand function shows the relationship between industry price and the entrants' output, assuming (in accordance with the zero conjectural variation assumption) the incumbent maintains its output at . The residual demand function is equivalent to the segment of the market demand function that lies to the right of . Since the residual demand function lies below at all output levels, the entrants conclude they cannot earn a normal profit and abstain from entry. The incumbent's position at , and its abnormal profit of , are sustainable in both the pre-entry and post-entry periods. exceeds , the long-run abnormal profit in the previous case where the incumbent starts at ( ) and allows entry to take place. 输出增加到 以上，导致价格降至 以下。新进入者的剩余需求函数显示了行业价格与新进入者产量之间的关系，假设（根据零猜测变化假设）现有企业将其产量维持在 。剩余需求函数等同于市场需求函数中位于 右侧的部分。由于剩余需求函数在所有产量水平上都低于 ，新进入者得出结论他们无法获得正常利润并放弃进入。现有企业在 处的地位以及其 的异常利润，在进入前和进入后期均可持续。 超过 ，在前一情况中现有企业从（ ）开始并允许进入发生时的长期异常利润。
Figure 12.4 shows the limit pricing model in the case of an economies of scale entry barrier. In this case, it is more natural to consider the case of a single incumbent and a single entrant (rather than a fringe of small competitive entrants), because both firms would need to operate at a reasonably large scale in order to benefit from economies of scale. For simplicity, only the limit pricing solution (and not the comparison with the monopoly pricing solution) is shown. LRAC is the average cost function of both the incumbent and the entrant. The incumbent can prevent entry by operating at . As before, the residual demand function is the entrant's effective demand function when the incumbent is producing , equivalent to the section of the market demand function to the right of . The residual demand function lies below LRAC at all output levels. If the entrant produces a low output, it fails to benefit from economies of scale. If the entrant produces a high output, it benefits from economies of scale, but the extra output causes price to drop to a level that is unprofitable. Therefore the entrant concludes it cannot earn a normal profit at any output level, and abstains from entry. 图 12.4 展示了在规模经济进入壁垒情况下的限价模型。在这种情况下，更自然地考虑单一现有企业和单一新进企业的情况（而不是一群小竞争性新进企业），因为两家公司都需要以相当大的规模运营才能从规模经济中受益。为简单起见，只显示了限价解决方案（而不是与垄断定价解决方案的比较）。LRAC 是现有企业和新进企业的平均成本函数。现有企业可以通过在 运营来阻止新进企业进入。与以前一样，剩余需求函数是新进企业的有效需求函数，当现有企业生产 时，相当于市场需求函数右侧的部分。剩余需求函数在所有产出水平都低于 LRAC。如果新进企业产出较低，则无法从规模经济中受益。如果新进企业产出较高，则会从规模经济中受益，但额外产出会导致价格降至无利可图的水平。 因此，参与者得出结论，无法在任何产出水平上获得正常利润，并放弃进入。
There is limited empirical evidence concerning the use or effectiveness of limit pricing strategies. Much of the evidence that is available is anecdotal. For 关于限价策略的使用或有效性，目前有限的实证证据。大部分可获得的证据都是轶事。对于
Figure 12.4 Limit pricing to deter entry: economies of scale 图 12.4 限价以阻止进入：规模经济
example, Scherer and Ross (1990) observe that the pricing policy of the Reynolds Pen Corporation, manufacturers of the first ballpoint pens, invited entry on a large scale. In 1945 the price was between US and US , but by 1948 the price had fallen to 50 cents and Reynolds' market share was close to zero. In the 1960s Xerox implemented a strategy of charging low prices to low-volume users (less than 5,000 copies per month). An alternative technology (wet copying) was available, and Xerox's pricing strategy was designed to deter low-volume users from switching to this alternative product. Yamawaki (2002) examines how incumbent firms in the US luxury car market responded to threatened or actual entry from Japanese manufacturers during the period 1986-97. There was a tendency for incumbent firms to reduce prices and markups. However, surveys by Smiley (1988) and Singh et al. (1998) find limited evidence of the use of limit pricing as an entry-deterring strategy. 例如，Scherer 和 Ross（1990）观察到雷诺兹钢笔公司的定价政策，这家公司是第一家生产圆珠笔的制造商，吸引了大规模进入。1945 年，价格在 0 美元和 1 美元之间，但到 1948 年，价格已降至 50 美分，雷诺兹的市场份额接近零。20 世纪 60 年代，施乐实施了一项策略，向低容量用户（每月少于 5,000 份复印件）收取低价。另一种技术（湿复印）是可用的，施乐的定价策略旨在阻止低容量用户转向这种替代产品。Yamawaki（2002）研究了美国豪华汽车市场的现有公司如何应对 1986-97 年间来自日本制造商的威胁或实际进入。现有公司有降低价格和利润率的倾向。然而，Smiley（1988）和 Singh 等人（1998）的调查发现，限制定价作为一种阻止进入的策略的证据有限。
Stigler (1968) and Yamey (1972) criticise the theory of limit pricing on the following grounds: Stigler（1968）和 Yamey（1972）批评限制定价理论的理由如下：
Why is it more profitable to attempt to restrict all entry rather than retard the rate of entry? 为什么尝试限制所有进入而不是减缓进入速度更具盈利性？
Why should the entrant believe the incumbent would not alter its pricing and output policies if entry takes place? 如果进入者相信现有企业不会改变其定价和产出政策，那么为什么会有进入者？
If an industry is growing, it may be difficult to persuade a potential entrant that there is no market available if entry takes place. 如果一个行业正在增长，可能很难说服潜在的进入者，如果进入发生，市场上没有可用的市场。
Market structure is ignored. Applied to the case of oligopoly, the theory assumes all incumbent firms would implement a limit-pricing strategy. For this strategy to succeed, a high level of coordination or collusion would be required. 忽略了市场结构。应用于寡头垄断的情况，理论假设所有现有企业都会实施限价策略。为了使这种策略成功，需要高度的协调或勾结。
Limit pricing implies perfect information regarding the market demand function, the incumbent's own costs, the entrants' costs and so on. These would be impossible to estimate with any degree of precision. Predatory pricing (see below) might offer an easier alternative: the incumbent would simply set a price below that of the entrant until the entrant withdraws. 限价意味着对市场需求函数、现有企业自身成本、新进入者成本等具有完美信息。这些是不可能以任何程度的精确度估计的。掠夺性定价（见下文）可能提供一个更容易的选择：现有企业只需将价格设定在新进入者的价格之下，直到新进入者退出。
The status of the entrant is all-important. An incumbent may wish to seek an accommodation with a large potential entrant. 新进入者的地位至关重要。现有企业可能希望与一个潜在的大型新进入者达成协议。
Predatory pricing 掠夺性定价
A strategy of predatory pricing on the part of an incumbent firm involves cutting price in an attempt to force a rival firm out of business. When the rival has withdrawn, the incumbent raises its price. The incumbent adopts the role of predator, sacrificing profit and perhaps sustaining losses in the short run, in order to protect its market power and maintain its ability to earn abnormal profit in the long run. For example, Bresnahan and Reiss (1991), Joskow et al. (1994) and Marion (1998) report evidence of price-cutting by incumbents, following entry into the tyre, airline and grocery industries, respectively. Strictly speaking, predatory pricing is a post-entry strategy. However, an incumbent faced with threatened entry might attempt to ward off the threat by convincing the potential entrant it would 一家现有公司采取的掠夺性定价策略涉及削减价格，试图迫使竞争对手退出市场。当竞争对手退出后，现有公司会提高价格。现有公司扮演掠夺者的角色，短期内牺牲利润甚至承受损失，以保护其市场地位并保持长期赚取异常利润的能力。例如，Bresnahan 和 Reiss（1991 年）、Joskow 等人（1994 年）和 Marion（1998 年）报告了现有公司在轮胎、航空和食品杂货行业进入后削价的证据。严格来说，掠夺性定价是一种后入市策略。然而，面临潜在进入威胁的现有公司可能会试图通过说服潜在进入者，表示如果进入市场，将实施掠夺性定价政策来抵御威胁（Myers，1994 年；Ordover，2008 年）。
implement a predatory pricing policy in the event that entry takes place (Myers, 1994; Ordover, 2008). 在进入发生时，一家现有公司可能会实施掠夺性定价政策，以防止潜在进入者。
Faced with the threat or the actuality of price-cutting on the part of a predator, how might an entrant or another rival firm respond? The rival might be able to convince the predator it is in their mutual interest to merge, or find some other way of sharing the market between them. Alternatively, the rival might be able to convince customers it is not in their interest to accept price cuts from the predator in the short run, if the consequence is that the predator achieves monopoly status in the long run. 面对掠食者威胁或实际降价，新进入者或其他竞争对手该如何应对？竞争对手可能说服掠食者，合并符合双方利益，或者找到其他方式在他们之间分享市场。另外，竞争对手也可以说服顾客，如果结果是掠食者最终实现垄断地位，短期内不接受掠食者的降价并不符合他们的利益。
Another possible response would be for the rival firm to reduce its output, forcing the predator to produce at an even higher volume than it might have planned, in order to maintain the reduced price. If the reduced price is below the predator's average variable cost, the predator's losses are increased, and the length of time over which it can sustain the price-cutting strategy might be reduced. If the rival firm does not have large sunk costs, it might be able to redeploy its assets to some other industry and (temporarily) withdraw altogether, in the expectation that it will return when the predator raises its price. 另一种可能的反应是竞争对手减少产量，迫使掠食者以比原计划更高的产量生产，以维持降价。如果降价低于掠食者的平均可变成本，掠食者的损失会增加，维持降价策略的时间可能会缩短。如果竞争对手没有大量沉没成本，它可能能够重新配置资产到其他行业，并（暂时）完全退出，期望当掠食者提价时再次回归。
The (anti-interventionist) Chicago school is rather sceptical about the reality of predatory pricing. First, the predator's gain in profit in the long run must exceed the loss resulting from price-cutting in the short run. It may be difficult for a predator to be certain this condition will be met. Second, for a predatory pricing strategy to succeed in deterring entry, the predator has to convince the entrant it is prepared to maintain the reduced price and sustain losses for as long as the entrant remains in business. It may be difficult or impossible for the predator to signal this degree of commitment to the entrant. Third, as suggested above, for a predatory pricing strategy to be worthwhile, the predator has to be sure that having forced its rival out of business and raised its price, the entry threat will not return, either in the form of the same rival or some other firm. To prevent this from happening, the predator might attempt to acquire the rival's assets. Finally, if an incumbent and an entrant have identical cost functions, a predatory pricing strategy could just as easily be used by the entrant against the incumbent as the other way round. Therefore, predatory pricing is not necessarily or solely an entry-deterring strategy. 芝加哥学派对掠夺性定价的现实性持怀疑态度。首先，掠夺者长期获利必须超过短期降价造成的损失。掠夺者可能很难确定这个条件是否会得到满足。其次，为了成功地阻止进入市场，掠夺性定价策略必须让新进入者相信它准备维持降价并承受损失，只要新进入者继续经营。掠夺者可能很难或不可能向新进入者传递这种承诺的程度。第三，如上所述，为了使掠夺性定价策略值得，掠夺者必须确保在迫使竞争对手退出市场并提高价格后，进入威胁不会再次出现，无论是同一竞争对手还是其他公司的形式。为了防止这种情况发生，掠夺者可能会试图收购竞争对手的资产。最后，如果现有企业和新进入者具有相同的成本函数，掠夺性定价策略可以被新进入者用来对付现有企业，就像反过来一样容易。 因此，掠夺性定价并不一定或仅仅是一种入市阻挡策略。
For regulators, it is often difficult to determine whether a specific price-cutting campaign constitutes predatory pricing, which is likely to be unlawful under competition legislation, or whether it constitutes a legitimate strategy to acquire market share that will also benefit consumers. From 26 proven cases of predatory competition in the US, in only six was there clear economic evidence of predatory pricing (Koller, 1975). 对于监管机构来说，往往很难确定特定的降价活动是否构成掠夺性定价，后者可能违反竞争立法，或者它是否构成一种合法策略来获取市场份额，从而也使消费者受益。在美国有 26 起被证实的掠夺性竞争案例中，只有六起存在明确的经济证据表明存在掠夺性定价（Koller，1975 年）。
Brand proliferation 品牌扩张
For many product types, a certain amount of product differentiation is quite natural, in view of basic product characteristics and consumer tastes (see Section 12.2). In some imperfectly competitive markets, however, incumbents may employ advertising or other types of marketing campaign to create or strengthen brand loyalties beyond what is natural, in order to raise the start-up 对于许多产品类型来说，根据基本产品特性和消费者口味，一定程度的产品差异化是非常自然的（见第 12.2 节）。然而，在一些不完全竞争的市场中，现有企业可能会利用广告或其他类型的营销活动来创造或加强超出自然水平的品牌忠诚度，以提高新进入者面临的启动成本。
costs faced by entrants. A firm wishing to establish a new brand would incur significant sunk costs in the form of advertising and other promotional expenditure. 一个希望建立新品牌的公司将会在广告和其他促销支出形式上承担重大的沉没成本。
Brand proliferation, or spurious product differentiation, refers to efforts by an incumbent firm to crowd the market with similar brands, denying an entrant the opportunity to establish a distinctive identity for its own brand. This form of entry-deterring strategy is common in markets for products such as detergents and processed foods. From the incumbent's perspective, however, a strategy of brand proliferation could simply cannibalise existing brands. The incumbent firm might also raise its own average costs relative to those of an entrant (Spulber, 2003). 品牌扩张或虚假产品差异化是指现有企业努力在市场上推出类似品牌，从而剥夺新进入者为自己品牌建立独特身份的机会。这种入市阻挡策略在洗涤剂和加工食品等产品市场中很常见。然而，从现有企业的角度来看，品牌扩张策略可能只是在内部品牌之间互相蚕食。现有企业还可能提高自身的平均成本，相对于新进入者的成本（Spulber，2003）。
Advertising can help raise barriers to entry. An incumbent firm may benefit from an absolute cost advantage in advertising if its past advertising investment has helped establish name recognition or brand loyalty among consumers. Consumer familiarity makes current advertising more effective than it is for an entrant attempting to establish a presence in the market for the first time. Economies of scale in advertising may also make it difficult for small-scale entrants to compete effectively with incumbents who are already producing and advertising on a large scale. 广告可以帮助提高准入壁垒。如果过去的广告投资帮助建立了消费者的知名度或品牌忠诚度，现有公司可能会从广告的绝对成本优势中受益。消费者的熟悉度使得当前的广告比试图在市场上首次建立存在的新进入者更有效。广告的规模经济也可能使得小规模新进入者难以有效地与已经大规模生产和广告的现有公司竞争。
Using a sample of 800 advertising managers, Paton (2008) investigates the extent to which managers perceive actual or potential entry in determining the level of advertising. Nearly 25 per cent of the firms in the sample stated that they attributed importance to entry deterrence as an aim of their advertising. In addition, over 20 per cent of firms responded that they would increase advertising expenditure in response to the entry of a rival product or service. 使用 800 名广告经理的样本，Paton（2008 年）调查了经理们在确定广告水平时认为实际或潜在准入的程度。样本中近 25%的公司表示，他们认为广告的一个目的是阻止准入。此外，超过 20%的公司回应称，他们会在竞争对手推出新产品或服务时增加广告支出。
Existing brand loyalties, and therefore entry barriers, are strengthened in cases where consumers incur significant switching costs associated with switching to another supplier. Customers with high switching costs are committed to remaining with their existing suppliers, and cannot easily be lured elsewhere (see Section 12.2). 在消费者需要付出巨大的转换成本才能转向另一供应商时，现有品牌忠诚度和因此而加强的进入壁垒会得到加强。具有较高转换成本的客户会决心继续与现有供应商合作，不容易被其他地方吸引（见第 12.2 节）。
Loyalty discounts, exclusive dealing and refusal to supply are all strategies intended to deny entrants access to supplies of inputs or access to customers. For example, the London radio station Capital Radio's practice of offering exclusivity deals to advertisers was investigated by the UK's Office of Fair Trading in 1994. In return for agreeing to advertise exclusively on Capital Radio, the advertiser received a discount. The effect of these agreements was to exclude Capital's competitors from a significant segment of the radio advertising market (OFT, 1994). A similar case involved petrol retailing in the UK in the 1960s, when many independent retailers signed long-term contracts to receive petrol supplies from a sole supplier. Vertical relationships of this kind are examined in Chapter 21. 忠诚度折扣、独家交易和拒绝供应都是旨在阻止新进入者获得输入物资或接触客户的策略。例如，伦敦广播电台 Capital Radio 向广告商提供独家交易的做法在 1994 年受到了英国公平交易办公室的调查。广告商同意在 Capital Radio 上独家广告，作为回报，广告商获得了折扣。这些协议的效果是排除了 Capital 的竞争对手在广播广告市场的一个重要部分（OFT，1994）。类似的案例发生在 20 世纪 60 年代的英国的汽油零售业，当时许多独立零售商签订了长期合同，从唯一供应商那里获得汽油供应。这类垂直关系在第 21 章中进行了研究。
12.4 Signalling commitment 12.4 表明承诺
Dixit (1982) uses a game-theoretic model to describe a situation in which an incumbent firm attempts to deter entry by deliberately increasing its sunk cost expenditure before entry takes place. The incumbent creates and signals a commitment to fight entry by engaging the entrant in a price war, in the event that entry subsequently occurs. Dixit（1982）使用博弈论模型来描述这样一种情况：现有企业试图通过在进入之前故意增加其沉没成本支出来阻止进入。现有企业通过在价格战中与新进入者进行交锋来创造并传达对抗进入的承诺，以防后来真的发生进入。
Figure 12.5 Sequential entry game 图 12.5 顺序进入博弈
A passive incumbent does not pre-commit to fighting the entrant, in the event that entry subsequently takes place. In other words, a passive incumbent waits to see if entry occurs, before investing in the additional productive capacity or the aggressive marketing campaign that will be required to fight a price war. In contrast, a committed incumbent does pre-commit, by incurring the sunk cost expenditure that will be required to fight in advance, before it knows whether or not entry will actually take place. Figure 12.5 shows the array of possible outcomes in a sequential game (see also Section 9.5) played by an incumbent and an entrant, in the form of realised final profits or losses for each firm. These depend upon whether the incumbent is passive or committed, and upon whether entry actually does occur. 被动的现有企业不会预先承诺与新进入者交锋，以防后来真的发生进入。换句话说，被动的现有企业会等待看看是否发生进入，然后再投资于必要的额外生产能力或激进的营销活动，以便进行价格战。相比之下，有承诺的现有企业会预先承诺，通过提前支出所需的沉没成本支出来进行对抗，而不管是否真的会发生进入。图 12.5 展示了现有企业和新进入者进行的顺序博弈（另见第 9.5 节），以实现最终利润或损失的可能结果。这些结果取决于现有企业是被动的还是有承诺的，以及进入是否真的发生。
Passive incumbent 被动现有者
Suppose the incumbent is passive. If the entrant stays out, the incumbent earns the monopoly profit and the entrant earns zero. In Figure 12.5, this outcome is denoted . If entry does occur, the incumbent can either fight a price war or accommodate the entrant by sharing the market. In the event of a price war, both firms earn a loss of . This outcome is denoted . In the event that the firms share the market, both earn duopoly profit and the outcome is . It is assumed and . 假设现有者是被动的。如果新进入者不进入，现有者将获得垄断利润，而新进入者将获得零利润。在图 12.5 中，这一结果表示为 。如果确实发生了进入，现有者可以选择进行价格战，或者与新进入者分享市场。在价格战中，两家公司都会蒙受损失 。这一结果表示为 。如果两家公司选择分享市场，都将获得双头垄断利润，结果为 。假设 和 。
In this case, the incumbent might attempt to threaten the entrant with the prospect of a price war in the event that entry occurs. However, if the entrant has perfect knowledge of the array of outcomes shown in Figure 12.5, the entrant will realise this threat is not credible. Suppose entry actually does occur. At that point, the incumbent is faced with the choice of either fighting, in which case it 在这种情况下，现有者可能会试图以价格战的前景威胁新进入者，以防发生进入。然而，如果新进入者对图 12.5 中显示的各种结果有完全的了解，新进入者将意识到这种威胁是不可信的。假设实际上发生了进入。此时，现有者面临着要么进行对抗的选择，
suffers a loss of , or accommodating, in which it earns a profit of . In other words, if entry actually does take place, it makes no sense for the incumbent to carry out the threat to fight. Realizing this and attracted by the prospect of a profit of , the entrant proceeds, and is the final outcome. 遭受 的损失，或者容忍，从中获得 的利润。换句话说，如果实际发生进入，现任者执行威胁战斗就没有意义。认识到这一点，并被 的利润前景吸引，新进者继续前进， 是最终结果。
Committed incumbent 忠诚的现任者
Suppose the incumbent is committed rather than passive, and incurs sunk cost investment expenditure of . In this case, if the entrant stays out, the incumbent's monopoly profit is reduced as a result of having incurred the sunk cost expenditure. As before, the entrant earns zero. In Figure 12.5, this outcome is denoted . If entry does occur, as before, the incumbent can either fight a price war or accommodate and share the market. In the event of a price war, the outcome is ( ). Crucially, the fact that the sunk cost expenditure needed to fight was incurred in advance does not affect the incumbent's realised losses if the price war occurs. In the event that the firms share the market, the outcome is . It is assumed and . 假设现任者是忠诚的而不是被动的，并且承担了 的沉没成本投资支出。在这种情况下，如果新进者不参与，现任者的垄断利润会因为已经发生了沉没成本支出而减少。与之前一样，新进者获得零。在图 12.5 中，这种结果被标记为 。如果发生进入，与之前一样，现任者可以选择进行价格战或者容忍并分享市场。在价格战的情况下，结果是（ ）。至关重要的是，事先发生的用于战斗的沉没成本支出不会影响现任者如果价格战发生时实现的损失。如果公司分享市场，结果是 。假设 和 。
In this case, the incumbent's threat to launch a price war is credible. Suppose entry actually does occur. At that point, the incumbent is faced with the choice of either fighting, in which case it earns a loss of , or accommodating, in which it earns an even greater loss of . This time, if entry actually takes place, it makes sense for the incumbent to carry out the threat to fight. Faced with the prospect of suffering a loss of if it proceeds, the entrant is deterred, and is the final outcome. 在这种情况下，现任者发动价格战的威胁是可信的。假设实际上发生了进入。在那时，现任者面临着要么战斗的选择，这样它会蒙受 的损失，要么让步，这样它会蒙受更大的 的损失。这一次，如果实际上发生了进入，现任者有理由执行战斗的威胁。面临着如果继续进行将遭受 的损失的前景，新进入者被吓阻了， 是最终结果。
For a numerical illustration of this model, let and . Summarizing the logic of the previous paragraphs, if the incumbent is passive and entry takes place, the incumbent realises -20 by fighting and 20 by accommodating. Therefore, post-entry, it is in the incumbent's interests to accommodate. Faced with the prospect of realizing a profit, the entrant proceeds and the final outcome is . If the incumbent is committed and entry takes place, the incumbent realises -20 by fighting and -40 by accommodating. Therefore, post-entry, it is in the incumbent's interests to fight. Faced with the prospect of realizing a loss, the entrant does not proceed and the final outcome is . 对于这个模型的数值说明，让 和 。总结前几段的逻辑，如果现有企业被动且有新进入者，现有企业通过战斗实现-20，通过容忍实现 20。因此，进入后，现有企业有利于容忍。如果现有企业是有决心的且有新进入者，现有企业通过战斗实现-20，通过容忍实现-40。因此，进入后，现有企业有利于战斗。面对盈利前景，新进入者继续，最终结果是 。如果现有企业是有决心的且有新进入者，现有企业通过战斗实现-20，通过容忍实现-40。因此，进入后，现有企业有利于战斗。面对亏损前景，新进入者不继续，最终结果是 。
Are there any circumstances in which the incumbent could remain passive (avoiding incurring the sunk cost expenditure), but still be successful in deterring entry? Dixit (1982) discusses the case in which the game described in Figure 12.5 is repeated an infinite number of times. In this case, it might be in the interests of an incumbent who is passive in each period (as defined above) to fight whenever entry actually occurs, in order to establish a reputation for fighting. Observing that the incumbent always reacts by fighting, the entrant learns from experience that there is nothing to be gained by entering, and abstains from doing so. As shown in Section 7.6, however, this type of model unravels if there is a limit to the number of times the game is repeated. Reputation then becomes unimportant in the final period, when there is no incentive for the incumbent to fight. Knowing this, the entrant proceeds in the final period. But this implies reputation also becomes unimportant in the penultimate period, so the entrant proceeds then as well, and so on. 在某些情况下，现任者可以保持被动（避免产生沉没成本支出），但仍然成功地阻止进入吗？Dixit（1982）讨论了在图 12.5 中描述的游戏被重复无限次的情况。在这种情况下，对于每个周期都保持被动的现任者（如上所定义），当实际发生进入时，可能有利于进行战斗，以建立战斗的声誉。观察到现任者总是通过战斗做出反应，进入者从经验中学到，进入没有任何好处，因此放弃进入。然而，如第 7.6 节所示，如果游戏重复的次数有限，这种模型就会崩溃。在最后一个周期中，声誉变得不重要，现任者没有动机进行战斗。了解到这一点，进入者会在最后一个周期中进行。但这意味着声誉在倒数第二个周期中也变得不重要，因此进入者也会在那时进行，依此类推。
In the setting of a repeated entry game, another case in which a passive incumbent might succeed in deterring entry (without incurring sunk cost expenditure) occurs if there is imperfect knowledge, and the entrant does not know whether the incumbent is passive or committed. An incumbent who is actually passive might attempt to deceive the entrant into believing the incumbent is committed, by launching a price war in the event that entry takes place. After observing a fighting response in one period, and knowing that a committed incumbent always fights, the entrant's subjective probability that the incumbent is committed increases, making it less likely that the entrant will decide to proceed in subsequent periods. 在重复进入博弈的背景下，另一种被动现有企业可能成功阻止进入的情况（而不产生沉没成本支出）是存在不完全信息的情况，而进入者不知道现有企业是被动还是承诺的。实际上是被动的现有企业可能会试图欺骗进入者，让其相信现有企业是承诺的，方法是在发生进入时发动价格战。在一个时期观察到对抗性反应后，知道承诺的现有企业总是会对抗，进入者对现有企业是承诺的主观概率增加，从而使得进入者更不可能在随后的时期决定继续前进。
Alternatively, incumbent firms can attempt to deter potential entrants by announcing new versions of existing products well in advance of their actual launch. This deters potential entrants from developing similar products, as they may anticipate it will be unprofitable to do so. Haan (2003) cites a number of instances of so-called vaporware (excessively early announcement of a new version of a product) in the information technology industry. These include Microsoft's Windows 2000 (promised in 1997 but not launched until 2000) and Intel's 64-bit Itanium chip (promised in early 2000 but not launched until 2001). 或者，现有公司可以尝试通过提前宣布现有产品的新版本来阻止潜在的新进入者。这会阻止潜在的新进入者开发类似的产品，因为他们可能预计这样做是不赚钱的。Haan（2003）引用了一些所谓的虚拟软件（过早宣布新版本产品）的例子，这些例子出现在信息技术行业。其中包括微软的 Windows 2000（1997 年承诺，但直到 2000 年才推出）和英特尔的 64 位 Itanium 芯片（2000 年初承诺，但直到 2001 年才推出）。
12.5 Potential entry and contestability 12.5 潜在进入和可竞争性
The theory of contestable markets, originally developed by Baumol et al. (1982), considers an industry comprising a small number of incumbent firms or a single incumbent, whose market power is constrained by the threat of potential entry. Despite the fact that the incumbents are few in number, the entry threat forces them to keep their prices at a relatively low level, and constrains their ability to earn abnormal profits. Accordingly, even in highly concentrated industries, it is possible that incumbent firms can earn only a normal profit, because of threatened competition from potential entrants. The presence of a large number of competing firms is not a necessary condition for industry price and output to be set at a level consistent with perfect competition; threatened competition from potential entrants may be sufficient to produce the same effect. 竞争市场理论最初由鲍默尔等人（1982 年）提出，考虑到一个由少数现有公司或单一现有公司组成的行业，其市场力量受到潜在进入的威胁的限制。尽管现有公司数量不多，但进入威胁迫使它们保持相对较低的价格水平，并限制它们赚取异常利润的能力。因此，即使在高度集中的行业中，现有公司也可能只能赚取正常利润，因为潜在进入者的竞争威胁。存在大量竞争公司并非行业价格和产出设定在与完全竞争一致的水平上的必要条件；潜在进入者的竞争威胁可能足以产生相同的效果。
For a market to be perfectly contestable, there must be no significant entry or exit barriers. The theory of contestable markets therefore excludes structural entry barriers, entry-deterring strategies on the part of incumbent firms, and sunk costs. Baumol et al. introduce the idea of hit-and-run entry, based on the following assumptions: 要使市场完全具有竞争性，就不能存在重大的进入或退出壁垒。因此，竞争性市场理论排除了结构性进入壁垒、现有公司采取的阻止进入的策略以及沉没成本。鲍姆等人提出了“闪电进入”的概念，基于以下假设：
A potential entrant can identify consumers who will purchase its output at or below the current market price. 潜在的新进入者能够确定那些愿意以当前市场价格或以下价格购买其产品的消费者。
The entrant has sufficient time to sell to these consumers before the incumbent has time to react. 新进入者有足够的时间向这些消费者销售产品，而现有公司还没有时间做出反应。
At the prices quoted, the entrant earns sufficient revenue to cover its fixed and variable costs. 在所报价格下，参与者赚取足够的收入来支付其固定成本和变动成本。
For unrecoverable investments, the length of time for which the asset is employed is important. If the asset can be used solely in the current period, the sunk costs are essentially a current fixed cost. The ability to recover all costs quickly is a defining characteristic of a contestable market, because if sunk costs cannot be recovered quickly, the incumbent has the opportunity to respond to the entrant's presence strategically. By cutting price aggressively, the incumbent might be able to make the entrant's continuing operation unprofitable. If hit-and-run entry is profitable, however, the entrant can move in and realise its profit before the incumbent has time to react. 对于无法收回的投资，资产被使用的时间长度很重要。如果资产仅能在当前期间使用，沉没成本本质上是一种当前固定成本。快速收回所有成本的能力是可争夺市场的一个定义特征，因为如果沉没成本无法迅速收回，现有企业有机会对参与者的存在做出战略性回应。通过大幅降价，现有企业可能能够使参与者的持续运营变得不盈利。然而，如果投机性进入是盈利的，参与者可以在现有企业有时间做出反应之前进入并实现其利润。
Goolsbee and Syberson (2008) use data from the US Department of Transportation to assess how established firms respond to the threat of entry of competitors in the US Airline Industry. The evolution of Southwest Airlines' route network is examined to identify routes where the probability of future entry rises abruptly. Incumbents on threatened routes cut prices significantly when threatened by Southwest's incursion into their markets. Goolsbee 和 Syberson（2008）使用美国交通部的数据来评估已建立公司如何应对美国航空业竞争对手的威胁。研究了西南航空公司的航线网络演变，以确定未来进入概率急剧上升的航线。当现有公司受到西南航空公司进入市场的威胁时，受威胁航线上的现有公司大幅降价。
Graham et al. (1983), Call and Keeler (1985), Moore (1986) and Morrison and Winston (1987) discuss some of the limitations of the theory of contestable markets. Graham 等人（1983 年），Call 和 Keeler（1985 年），Moore（1986 年）和 Morrison 和 Winston（1987 年）讨论了可争夺市场理论的一些局限性。
The exclusion of sunk costs is generally unrealistic, as entry into most markets requires a significant amount of sunk cost investment. There are some possible exceptions (see below), but in most industries 'sunk costs are found to weaken the support for "strong" interpretations of the contestable market hypothesis and thus yield a wide diversity of dynamic patterns of market performance' (Coursey et al., 1984, p. 69). 排除沉没成本通常是不现实的，因为进入大多数市场都需要大量的沉没成本投资。有一些可能的例外情况（见下文），但在大多数行业中，“发现沉没成本削弱了对可争夺市场假设的‘强’解释的支持，从而产生了广泛的市场绩效动态模式”（Coursey 等人，1984 年，第 69 页）。
By restricting the analysis to the short-run period within which the incumbent does not have sufficient time to respond, the reaction of the incumbent to attempted hit-and-run entry is excluded by assumption. Schwartz and Reynolds (1983) argue that an analysis of entry should focus not on the existing price charged by incumbents before entry, but on the post-entry price. 'The theory is naïve and static, with only one price. It ignores possible strategic price discrimination by the incumbent, which would decisively defeat entry while permitting excess profits' (Shepherd, 1997, p. 220). 通过将分析限制在短期内，在这段期间内，现任者没有足够的时间做出反应，对企图的闪击式进入的现任者的反应被假设排除在外。 Schwartz 和 Reynolds（1983）认为，对进入的分析不应该集中在现任者进入之前的现有价格上，而应该集中在进入后的价格上。'这个理论是天真和静态的，只有一个价格。它忽视了现任者可能进行的战略性价格歧视，这将彻底击败进入，同时允许超额利润'（Shepherd，1997，第 220 页）。
The assumption that the potential entrant faces no cost disadvantage relative to the incumbent is unrealistic. The latter may have acquired technical expertise and built up goodwill in the past. 潜在进入者与现任者面临相同的成本劣势的假设是不现实的。后者可能在过去获得了技术专长并积累了商誉。
Commercial airline services and bus services on specific routes have been viewed as promising testing grounds for contestable markets theory. While the construction of an airport or a bus station represents a form of sunk cost investment (since these assets cannot be moved geographically), the purchase of a fleet of aircraft or buses by a service provider does not entail sunk costs. Such assets can easily be transferred from one route to another, making hit-and-run entry (on the part of service providers) a realistic possibility. 商业航空公司服务和特定路线上的公共汽车服务被视为竞争市场理论的有前途的试验场。虽然建造机场或汽车站代表了一种沉没成本投资（因为这些资产无法地理性地移动），但服务提供商购买一批飞机或公共汽车并不涉及沉没成本。这些资产可以轻松地从一条路线转移到另一条路线，这使得服务提供商的闪电式进入成为一个现实可能。
Several researchers have subjected contestable markets theory to empirical scrutiny using data on commercial airlines. Hurdle et al. (1989) test for contestability in 867 airline routes in 1985. Regression analysis is used to examine the effects of potential entry and industry concentration on the level of fares charged on any 几位研究人员利用商业航空公司的数据对竞争市场理论进行了实证研究。Hurdle 等人（1989 年）在 1985 年对 867 条航线进行了竞争性测试。回归分析被用来检验潜在进入和行业集中对任何收费水平的影响。
specific route. Industry concentration, and not potential entry, is found to be the most important determinant of fares. Similarly, Strassmann (1990) tests for contestability using data on 92 US airline routes in 1980. If contestable markets theory is relevant, there should be no relationship between industry concentration and fares, or between entry barriers and fares. In a regression analysis, structural variables such as concentration and entry barriers are found to be the most significant determinants of fares. Therefore, both of these studies find that factors other than potential entry have the greatest influence on price. Neither study provides much support for the contestable markets theory. More recent evidence suggests established airlines benefit from learning economies of scale and brand loyalty advantages, which result in barriers to entry (Button and Stough, 2000; Johnson, 2003). 具体路线。发现行业集中度，而不是潜在进入，是票价的最重要决定因素。同样，Strassmann（1990）使用 1980 年 92 条美国航线的数据测试了可争夺性。如果可争夺市场理论是相关的，行业集中度与票价之间，或者进入壁垒与票价之间不应该有关系。在回归分析中，发现结构变量，如集中度和进入壁垒是票价的最重要决定因素。因此，这两项研究都发现，除了潜在进入之外的因素对价格影响最大。两项研究都没有为可争夺市场理论提供太多支持。更近期的证据表明，成熟的航空公司受益于学习规模经济和品牌忠诚度优势，这导致了进入壁垒（Button 和 Stough，2000；Johnson，2003）。
Accordingly, the practical relevance of contestable markets theory is questionable. Although the theory provides some insights concerning the possible behaviour of incumbents threatened by potential entry, early predictions that the notion of contestability might revolutionise the theory of the firm were wide of the mark. 因此，可争夺市场理论的实际相关性是值得怀疑的。尽管该理论提供了一些关于现有企业受到潜在进入威胁时可能行为的见解，但早期预测称可争夺性的概念可能会彻底改变公司理论是站不住脚的。
As often happens, a bright idea has been exaggeratedly oversold by its enthusiastic authors. The ensuing debate trims the concept and claims to their proper niche, taking their place among all the other ideas. In this instance, contestability offers insights, but it does not affect the central role of market structure. 正如经常发生的那样，一个好主意被热情的作者夸大宣传。随之而来的辩论将概念和主张修剪到适当的位置，使其在所有其他想法中占据一席之地。在这种情况下，可争夺性提供了见解，但并不影响市场结构的核心作用。
(Shepherd, 1997, p. 220) （Shepherd，1997 年，第 220 页）
12.6 Entry and industry evolution 12.6 进入和行业演变
Most of the models of entry and exit that have been examined in this chapter are static, in the sense that they are based on direct comparisons between a pre-entry and a post-entry market equilibrium. Essentially, entry is modelled either as a once-and-for-all game, or an equilibrating mechanism whose principal economic function is the elimination of abnormal profit. This approach is criticised by Carlton (2005), on the grounds that the abnormal profits that are earned in the short run (before entry takes place) may be of greater practical relevance than the long-run (post-entry) equilibrium in which only normal profits are realised. 本章中所研究的大多数进入和退出模型都是静态的，即它们基于对进入前后市场均衡的直接比较。基本上，进入被建模为一次性游戏，或者一个使异常利润消失的均衡机制。这种方法受到卡尔顿（2005）的批评，理由是在进入之前短期内获得的异常利润可能比长期（进入后）均衡更具实际相关性，后者只能实现正常利润。
The usual discussions of barriers to entry typically focus on the long run and ignore adjustment costs. In the short run, the concept of an entry barrier is not meaningful (since, by assumption, entry is not possible). But why is the long run of interest? Only because economists often slip into ignoring dynamics and go back to our simple models of short and long run. But as a practical matter, the long run may be of no interest whatsoever. It may take so long to get there that the persistence of supracompetitive profits until then turns out to be the fact of practical importance, not that these excess profits are eliminated in some far-off future year. 通常对于进入壁垒的讨论通常集中在长期，并忽略了调整成本。在短期内，进入壁垒的概念并不具有意义（因为根据假设，进入是不可能的）。但为什么长期很重要？只因为经济学家经常忽视动态，并回到我们简单的短期和长期模型。但实际上，长期可能根本不感兴趣。可能需要很长时间才能到达那里，因此，直到那时超竞争利润的持续性可能是实际重要性的事实，而不是这些过剩利润在某个遥远的未来年份被消除。
(Carlton, 2005, p. 10) （卡尔顿，2005 年，第 10 页）
In an attempt to address this kind of critique, and echoing some of the insights of Schumpeter (1928, 1942) and Geroski's (1991a) positions entry within a dynamic model of competition; in this context, entry and exit play a central role in shaping the evolution of industry structure in the long run. Geroski discusses two types of entry: 为了解决这种批评，并回应熊彼特（1928 年，1942 年）和杰罗斯基（1991a）的一些见解，将进入放在竞争的动态模型中；在这种情况下，进入和退出在塑造产业结构演变中发挥着中心作用。杰罗斯基讨论了两种类型的进入：
Imitative entry, which occurs when the entrant can earn a profit by copying an incumbent's product or method of production. Imitative entry is primarily an equilibrating force, in the sense that it helps propel the industry towards an equilibrium whose location and characteristics remain fundamentally unaltered. The incumbent's abnormal profit is reduced or eliminated as part of the adjustment process. 模仿性进入，指参与者通过复制现有企业的产品或生产方法而获利的情况。 模仿性进入主要是一种均衡力量，因为它有助于推动行业朝着一个基本上保持不变的均衡点前进。 调整过程中，现有企业的异常利润会减少或消失。
Innovative entry, which occurs when an entrant introduces a product with new characteristics, or finds a new method of producing an existing product more cheaply than before. Innovative entry is primarily a disruptive or disequilibrating force, in the sense that it changes the location and characteristics of an existing market equilibrium, and propels the industry in a new direction. 创新性进入，指参与者推出具有新特点的产品，或者找到一种比以前更便宜地生产现有产品的新方法的情况。 创新性进入主要是一种破坏性或非均衡力量，因为它改变了现有市场均衡的位置和特征，并推动行业朝着新方向发展。
Innovative entry in particular makes a crucial contribution to the formation and growth of new industries and the decline of old ones. Entry by more innovative or more efficient outsiders encourages incumbent firms to improve or replace their existing product lines, or reduce their costs. Competition will eventually force the withdrawal of incumbents that fail to innovate. 特别是创新性进入对新兴产业的形成和增长以及老旧产业的衰退起着至关重要的作用。 更具创新性或更高效的外部参与者的进入鼓励现有企业改进或替换其现有产品线，或降低成本。 竞争最终将迫使未能创新的现有企业退出。
Entry can also play a more creative role in markets, serving as a vehicle for the introduction and diffusion of innovations which embody new products or processes that fundamentally alter conditions of supply and demand. Further, the mere threat of entry of this type may induce incumbents to generate new innovations or to adopt existing ones more rapidly. 进入还可以在市场中发挥更具创造性的作用，作为引入和传播创新的载体，这些创新体现了根本改变供求条件的新产品或新流程。此外，这种类型的进入威胁本身可能促使现有企业更快地生成新创新或采用现有创新。
(Geroski, 1991a, p. 210) （Geroski，1991a，第 210 页）
The turnover of firms due to entry and exit is likely to be higher in technologyoriented industries such as electronics and pharmaceuticals, in which non-price competition tends to prevail. In these industries, variation in firm-level profit rates may be extreme, due to the uncertainties associated with the outcomes of innovation. Successful entrants may benefit significantly from first-mover advantages, which arise in several ways: 由于进入和退出而导致企业的营业额可能在技术导向型行业（如电子和制药行业）更高，这些行业往往存在非价格竞争。在这些行业中，由于创新结果的不确定性，企业层面的利润率变化可能极端。成功的新进入者可能会从先发优势中获益，这种优势以多种方式出现：
The first springs from its headstart in travelling down learning functions and exploiting economies of scale ... The second comes from the fact that first movers have an opportunity to monopolize scarce inputs ... Third, the purchase decisions of early consumers are effectively investments in learning about the product - what it does and how to use it - and when consumers have made such investments and are content with how the product works for them, they will be reluctant to try 第一个源于它在学习功能和利用规模经济方面的领先优势...第二个源于第一搬家者有机会垄断稀缺的投入...第三，早期消费者的购买决策实际上是对产品的学习投资 - 它的功能和如何使用它 - 当消费者做出这样的投资并对产品的使用感到满意时，他们将不愿尝试
alternatives .... Fourth and finally, first movers who bring a winning product to the market often enjoy an enhanced brand identity and status. 其他选择....第四，最后，将获得市场上获胜产品的先行者通常会享有增强的品牌身份和地位。
(Geroski, 2003, pp. 194-5) （Geroski，2003 年，第 194-5 页）
For example, Berger and Dick (2007) examine first-mover advantages for entrants into localised US banking markets during the period 1972-2002. The earlier a bank entered, the larger was its eventual market share relative to other banks. Long-lasting first-mover advantages were secured by building capacity through investment in branch networks. 例如，Berger 和 Dick（2007）研究了 1972-2002 年期间进入美国本地银行市场的先行者优势。银行越早进入，最终市场份额相对于其他银行就越大。通过投资分支网络来建立能力，可以获得持久的先行者优势。
12.7 Empirical evidence on entry 12.7 进入的实证证据
There is a substantial empirical literature on the determinants of entry in manufacturing (Siegfried and Evans, 1994). Typical findings are that rates of entry are relatively high in profitable industries and fast-growing industries (Baldwin and Gorecki, 1987; Geroski, 1991a,b). Rates of entry are relatively low in industries where incumbents have absolute cost advantages over potential entrants, or where entrants' capital requirements are substantial (Orr, 1974). However, evidence concerning the relationship between rates of entry and factors such as scale economies, excess capacity and incumbents' pricing practices (such as limit and predatory pricing) is both limited and inconclusive. 在制造业进入决定因素方面有大量实证文献（Siegfried 和 Evans，1994）。典型的研究结果是，盈利行业和快速增长行业的进入率相对较高（Baldwin 和 Gorecki，1987；Geroski，1991a，b）。在现有企业具有绝对成本优势或潜在进入者的资本需求巨大的行业中，进入率相对较低（Orr，1974）。然而，关于进入率与规模经济、过剩产能和现有企业的定价做法（如限制性和掠夺性定价）等因素之间的关系的证据既有限又不一致。
As discussed above, the size of barriers to exit depends on the level of sunk costs. A complete absence of sunk costs is unusual, given that many assets are specific, and cannot easily be transferred to other uses (Harbord and Hoehn, 1994). There is some manufacturing evidence to suggest that exit is higher when profits are low and sunk costs are insignificant (Dunne et al., 1988), although Schary (1991) finds no relationship between profitability and exit. Other characteristics of the firm's financial and operational structure may have more influence on the decision to exit. Deutsch (1984) suggests conflicts of objectives between owners and managers may make it difficult to achieve a decision to exit. It is also possible that there is a direct association between entry and exit rates, if there is a tendency for entrants to displace some incumbents. However, using US manufacturing data for the period 1963-82, Dunne et al. (1988) find a negative correlation between annual entry and exit rates. 如上所述，退出壁垒的大小取决于沉没成本的水平。鲜有完全没有沉没成本的情况，因为许多资产是特定的，不能轻易转移到其他用途（Harbord 和 Hoehn，1994）。有一些制造业的证据表明，当利润低且沉没成本微不足道时，退出率较高（Dunne 等，1988 年），尽管 Schary（1991 年）发现盈利能力与退出之间没有关系。公司财务和运营结构的其他特征可能对退出决策产生更大影响。Deutsch（1984）指出，所有者和经理之间的目标冲突可能会使达成退出决策变得困难。如果新进入者有取代一些现有企业的倾向，那么进入和退出率之间可能存在直接关联。然而，使用 1963-82 年间的美国制造业数据，Dunne 等人（1988 年）发现年度进入和退出率之间存在负相关。
In a well-known study, Orr (1974) examines the determinants of entry into 71 Canadian manufacturing industries for the period 1963-7. The regression model is as follows: 在一项著名的研究中，Orr（1974 年）研究了 1963-7 年间进入 71 个加拿大制造业的决定因素。回归模型如下：
is the average number of entrants in the sample period; is the average industry profit rate; is past industry growth; is the ratio of MES to industry sales (representing an economies of scale barrier to entry); is an estimated fixed capital entry requirement; is advertising intensity (ratio of advertising 是样本期间的平均参与者数量； 是平均行业利润率； 是过去的行业增长； 是 MES 与行业销售的比率（代表规模经济的进入壁垒）； 是估计的固定资本进入要求； 是广告强度（广告支出与行业销售的比率
expenditure to industry sales); is research and development intensity (ratio of research and development expenditure to industry sales); is the standard deviation of industry profit rates (representing business risk); is the level of industry concentration (measured on an ordinal scale: low , high ); and is total industry sales. ）； 是研发强度（研发支出与行业销售的比率）； 是行业利润率的标准差（代表业务风险）； 是行业集中度水平（按顺序刻度测量：低 ，高 ）； 是总行业销售。
Orr finds a positive relationship between each of and , and . Therefore, high values of profitability, growth and industry size are all associated with high rates of entry. Orr finds a negative relationship between each of , and , and . This constitutes evidence of entry barriers resulting from economies of scale, capital requirements, high advertising or research and development intensities, business risk and high industry concentration. Orr 发现每个 和 ，以及 之间存在正相关关系。因此，高利润率、增长和行业规模的高值都与高进入率相关联。Orr 发现每个 ， 和 ，以及 之间存在负相关关系。这构成了由规模经济、资本要求、高广告或研发强度、业务风险和高行业集中度导致的进入壁垒的证据。
Smiley (1988) and Bunch and Smiley (1992) examine entry-deterring strategies adopted by incumbents in new and established product markets. A total of 293 completed questionnaires were obtained from product managers, brand managers, directors of product management, division managers and marketing managers. Respondents were asked to identify the types of entry-deterring strategy they employed, and how frequently. In new product markets, entry-deterring strategies include: Smiley（1988 年）和 Bunch 和 Smiley（1992 年）研究了现有产品市场和新产品市场中现有企业采用的入市阻挡策略。共有 293 份完成的问卷来自产品经理、品牌经理、产品管理总监、部门经理和营销经理。受访者被要求确定他们采用的入市阻挡策略的类型以及频率。在新产品市场中，入市阻挡策略包括：
Charging low prices and spending heavily on advertising and promotion. 低价销售并大力投入广告和促销。
Building excess capacity as a signal that incumbents are able to meet future demand. 建立过剩产能作为现有企业能够满足未来需求的信号。
Pre-emptive patenting to prevent entrants from producing identical or similar products. 采取先发制人的专利策略，防止竞争对手生产相同或相似的产品。
Using the media to signal that entry would provoke retaliation. 利用媒体发出信号，表明进入市场会引发报复。
Engaging in limit pricing to make entry unprofitable. 采取限价策略，使竞争对手进入市场变得不盈利。
Additional strategies used in established product markets include: 在成熟产品市场中使用的其他策略包括：
Brand proliferation, intended to occupy product space, so that entrants cannot establish their own differentiated products or brands. 品牌多元化，旨在占据产品空间，使新进入者无法建立自己的差异化产品或品牌。
Masking the profitability of any single product line through the use of appropriate reporting practices in company accounts. 通过公司账目中适当的报告实践掩盖任何单一产品线的盈利能力。
For new products, advertising ( 78 per cent of firms) and pre-emptive patenting (71 per cent) were the most widely used entry-deterring strategies. Limit pricing was rarely used. There was little systematic difference between manufacturing and services, except that manufacturers were significantly more likely to use pre-emptive patenting. 对于新产品，广告（78%的公司）和先发专利（71%）是最常用的进入阻止策略。限价策略很少被使用。在制造业和服务业之间几乎没有系统性差异，唯一的例外是制造商更有可能使用先发专利。
For existing products, brand proliferation (79 per cent of firms), advertising (79 per cent) and masking the profitability of individual product lines ( 78 per cent) were the most widely used entry-deterring strategies. Building excess capacity was rarely used. Manufacturers were more likely than service firms to mask the profitability of product lines and to use pre-emptive patenting. Service firms 对于现有产品，品牌扩张（79%的公司）、广告（79%）和掩盖个别产品线的盈利能力（78%）是最常用的进入阻止策略。建立过剩产能很少被使用。制造商比服务公司更有可能掩盖产品线的盈利能力并使用先发专利。服务公司
typically concentrated on advertising and promotions and product differentiation to create brand loyalties. 通常专注于广告和促销以及产品差异化，以创造品牌忠诚度。
Khemani and Shapiro (1990) argue that entry is expected if an incumbent's current profit, denoted , exceeds the expected long-run profit, denoted . Exit is expected if current profit is below the expected long-run profit. Expressions for entry and exit are as follows: Khemani 和 Shapiro（1990）认为，如果现任公司的当前利润（表示为 ）超过预期的长期利润（表示为 ），则预期会有新公司进入市场。如果当前利润低于预期的长期利润，则预期会有公司退出市场。进入和退出的表达式如下：
ENT and EXT are the logarithms of the numbers of firms entering or exiting an industry; is the number of firms in the industry; and is an indicator variable for positive or negative values of . Observed patterns of entry and exit are found to correspond to this model specification. ENT 和 EXT 分别表示进入或退出行业的公司数量的对数； 表示行业中的公司数量； 是一个指示变量，表示 的正负值。观察到的进入和退出模式与该模型规范相对应。
Geroski (1991b) examines the extent of entry by domestic and foreign firms in 95 UK manufacturing industries for the period 1983-4. The number of entrants per industry was similar in both years, but the market share of entrants was relatively small (the average across industries was between 7 per cent and 8 per cent of total industry sales). On average, domestic entrants succeeded in capturing a higher market share than foreign entrants. Exit rates were relatively stable over time, but entry and exit rates were positively correlated, suggesting a displacement effect. High profitability and large industry size are reported to have encouraged entry, but (surprisingly) there was a negative relationship between industry growth and entry. The significance of these effects is greater for domestic entrants than for foreign entrants. Geroski（1991b）研究了 1983-4 年期间 95 个英国制造业行业国内外企业的进入程度。每个行业的新进入者数量在两年间相似，但新进入者的市场份额相对较小（各行业平均为总行业销售额的 7%至 8%）。平均而言，国内新进入者成功地占据了比外国新进入者更高的市场份额。退出率随时间相对稳定，但进入和退出率呈正相关，表明有一种置换效应。高盈利能力和大行业规模被报道为鼓励进入的因素，但（令人惊讶的是）行业增长与进入之间存在负相关关系。这些效应对国内新进入者的影响要大于对外国新进入者的影响。
Sleuwaegen and Dehandschutter (1991) examine the determinants of entry for 109 Belgian manufacturing industries for the period 1980-4. Schwalbach (1991) does the same for 183 German manufacturing industries for the period 1983-5. In these studies, entry rates are positively related to expected profits and industry growth, but negatively related to barriers in the form of initial capital requirements, and product differentiation advantages accruing to incumbents. For the early 1980s, Cable and Schwalbach (1991) report entry and exit rates for Belgium, Canada, Germany, Korea, Norway, Portugal, UK and US averaging at around 6.5 per cent of the relevant population of firms. Entry and exit rates also tend to be positively correlated with each other. Sleuwaegen 和 Dehandschutter（1991）研究了 1980-4 年间 109 家比利时制造业的进入决定因素。Schwalbach（1991）对 1983-5 年间的 183 家德国制造业进行了同样的研究。在这些研究中，进入率与预期利润和行业增长呈正相关，但与初始资本要求和产品差异化优势（对现有企业的优势）呈负相关。对于 1980 年代初，Cable 和 Schwalbach（1991）报告了比利时、加拿大、德国、韩国、挪威、葡萄牙、英国和美国的进入和退出率，平均约为所涉企业总数的 6.5%。进入和退出率也往往呈正相关。
Rudholm (2001) assesses the determinants of entry to 22 Swedish pharmaceutical markets between 1972 and 1996. Entry is higher in markets where incumbent firms earn high profits. Entry is lower in markets where incumbent firms enjoy long periods of patent protection. Overall, entrants tend to enjoy a high probability of survival. Rudholm（2001）评估了 1972 年至 1996 年间 22 个瑞典制药市场的进入决定因素。在现有企业获得高利润的市场中，进入率较高。在现有企业享有长期专利保护的市场中，进入率较低。总体而言，新进入者往往具有较高的生存概率。
Roberts and Thompson (2003) examine the population of Polish manufacturing firms drawn from 152 three-digit industries over the period 1991-3 to assess the determinants of entry and exit. Concentration, profitability, capital requirements and state ownership all tend to reduce entry. There is a positive Roberts 和 Thompson（2003）研究了来自 152 个三位数字行业的波兰制造企业的人口，以评估 1991-3 年间进入和退出的决定因素。集中度、盈利能力、资本需求和国有化都倾向于减少进入。进入率与行业规模、现有企业的先前退出率之间存在正相关。
association between the rate of entry and industry size, and the rate of previous exit of incumbent firms. Exit is less likely when concentration, industry growth and profitability are high, but more likely in large industries or in those with a past history of high entry and exit. 退出率较低，当集中度、行业增长和盈利能力较高时，但在大型行业或那些过去有高进入和退出历史的行业中更有可能。
Disney et al. (2003) examine the Annual Business Inquiry Respondents Database (ARD) for evidence on entry, exit and survival for UK manufacturing establishments over the period 1986-91. The results suggest small entrants are more likely to fail than their larger counterparts, but this danger recedes if fast growth is achieved. The rate of exit is higher for single establishments than for those that form part of a larger group. Disney 等人（2003）研究了英国制造企业 1986-91 年期间的年度商业调查受访者数据库（ARD），以了解进入、退出和生存的证据。结果表明，小型新进入者比其较大的同行更有可能失败，但如果实现快速增长，则这种风险会减少。单一企业的退出率高于那些属于较大集团的企业。
Using data on the market for tourist accommodation in Texas, Conlin and Kadiyali (2006) examine whether firms use excess capacity to deter entry. There is evidence of higher investment in capacity relative to demand in markets with higher concentration, and by firms with a larger market share. These findings are consistent with the hypothesis that firms with the most incentive to deter entry do so through the creation of spare capacity. 利用德克萨斯州旅游住宿市场数据，Conlin 和 Kadiyali（2006）研究企业是否利用过剩产能来阻止进入。在市场集中度较高的市场以及市场份额较大的企业中，存在相对于需求的投资增加的证据。这些发现与企业有最大激励来通过创造备用产能来阻止进入的假设一致。
Jeon and Miller (2007) examine the evolution of the population of US banks over the period 1978-2004. Entry of small banks occurred frequently, but only a small minority of these banks survived. Furthermore, exit of established banks (typically by merger) exceeded entry. Jeon 和 Miller（2007）研究了 1978 年至 2004 年间美国银行人口的演变。小银行的进入频繁发生，但只有少数小银行幸存下来。此外，成立银行的退出（通常是通过合并）超过了进入。
McGowan (2014) investigates whether the removal of entry barriers affects productivity. As a laboratory he uses the collapse of a sugar cartel in the US in the mid-1970s, which resulted in increased competition in the sugar beet industry. Following the demise of the cartel, the productivity of sugar beet producers improved markedly relative to a control group of other agricultural producers. McGowan（2014）调查了去除进入壁垒是否影响生产率。作为实验室，他使用了 20 世纪 70 年代中期美国糖业卡特尔的崩溃，导致甜菜产业竞争加剧。在卡特尔灭亡后，甜菜生产者的生产率相对于其他农业生产者的对照组显著提高。
Geroski (1995) presents a series of stylized facts on entry, based on accumulated past theoretical and empirical research: Geroski（1995）提出了一系列关于进入的程式化事实，这些事实基于过去累积的理论和实证研究：
Rates of entry by new firms are often high (relative to the numbers of incumbents), but new entrants rarely capture large market shares. 新公司的进入率通常很高（相对于现有公司的数量），但新进入者很少能够占据大市场份额。
Entry often leads to the displacement and exit of some incumbent firms. 进入通常会导致一些现有公司被取代和退出。
Small entrants are less likely to survive than large entrants. 较小的新进入者比较大的新进入者更不可能生存下来。
Entry by new firms is more common than entry by existing firms by means of diversification. However, diversified entrants are more likely to succeed. 新公司的进入比现有公司通过多元化进入更常见。然而，多元化的新进入者更有可能成功。
Entry rates tend to be high during the early stages of an industry's development, when consumer preferences are unsettled, and core brands, products and processes are not yet established. 在行业发展的早期阶段，当消费者偏好尚未确定，核心品牌、产品和流程尚未建立时，进入率往往较高。
Entry by new firms leads to increased competition, stimulates innovation and encourages incumbents to make efficiency savings. 新公司的进入导致竞争加剧，刺激创新并鼓励现有企业节约成本。
Incumbents tend to prefer non-price strategies to price strategies in order to deter entry. 现有企业倾向于采用非价格策略而不是价格策略来阻止进入。
Large or mature entrants are more likely to succeed than small or young entrants. 大型或成熟的新进入者比小型或年轻的新进入者更有可能成功。
Technology will hurt the banks, not kill them RT 技术将伤害银行，而不是消灭它们 RT
Technology has its eyes on banking. Apple is expected this week to launch Apple Pay, its touchless payment system for iPhones; venture capital funds are pouring money into 'fintech' start-ups; and Marc Andreessen, the technology entrepreneur, talks of 'a chance to rebuild the system. Financial transactions are just numbers; it's just information'. Andreessen, a partner of the venture fund Andreessen Horowitz, added in an interview with Bloomberg Markets magazine last week: 'To me, it's all about unbundling the banks. There are regulatory arbitrage opportunities every step of the way. If the regulators are going to regulate banks, then you'll have non-bank entities that spring up to do the things that banks can't do.' 技术将目光投向银行业。预计本周苹果将推出 Apple Pay，这是其面向 iPhone 的非接触式支付系统；风险投资基金正向“金融科技”初创企业注入资金；技术企业家马克·安德森谈到“重建系统的机会。金融交易只是数字；只是信息”。 安德森是风险基金安德森·霍洛维茨的合伙人，上周在接受彭博市场杂志采访时补充说：“对我来说，这一切都是关于拆分银行。每一步都存在监管套利机会。如果监管机构要监管银行，那么就会出现非银行实体来做银行无法做的事情。”
This raises plenty of questions, not least about the last time non-bank entities (also known as the shadow banking system) took over financial intermediation below the radar, stoking the 2008 financial crisis. But my question is: does Silicon Valley really want to blow up retail banking and create an entirely new financial system, or would it prefer to ride on the existing one? 这引发了许多问题，尤其是关于上次非银行实体（也被称为影子银行体系）在低调接管金融中介、引发 2008 年金融危机的情况。但我的问题是：硅谷是否真的想要摧毁零售银行并创建一个全新的金融体系，还是更愿意在现有体系上发展？
Aside from Bitcoin and cryptocurrency-related companies, in which Andreessen Horowitz invests, the evidence points firmly to the latter. Apple Pay sounds radical but is essentially a way to turn a phone into a contactless credit or debit card, with the support of US banks. Other start-ups are nibbling away at banks' more profitable services, not competing head-on. 除了比特币和与加密货币相关的公司外，安德森·霍洛维茨投资的证据明确指向后者。苹果支付听起来很激进，但实质上是一种将手机变成一张无接触信用卡或借记卡的方式，得到了美国银行的支持。其他初创公司正在逐步侵蚀银行更具盈利性的服务，而不是直接竞争。
There is no doubt that the infrastructure of retail banks is antiquated, and is built in a way that invites competition from peer-to-peer networks. Nor is there a doubt that banks make themselves vulnerable by how they price - offering core deposit services cheaply or free while squeezing customers on ancillary products such as overdrafts and currency exchange. But what is the best way to compete with an industry that makes little from a capital-intensive, regulated service with formidable barriers to entry, and a lot from less protected add-ons? The question answers itself, which is why Silicon Valley focuses on payments while talking about disrupting lending. 毫无疑问，零售银行的基础设施陈旧，建立的方式容易受到点对点网络的竞争。同样毫无疑问，银行通过定价使自己变得脆弱 - 在核心存款服务上提供廉价或免费的同时，在透支和货币兑换等附属产品上向客户施加压力。但是，如何与一个从资本密集、受监管的服务中获利甚微，而从较少受保护的附加服务中获利颇丰的行业竞争，这是最佳方式？问题的答案显而易见，这就是为什么硅谷专注于支付，同时谈论颠覆贷款。
Consider Occupy Wall Street, the protest movement that rightly focused attention on the unfairness of the banking industry's entrenchment and reliance on public finance. In the wake of the protests, a group of Occupiers tried and failed to set up a national credit union or bank in the US, and to launch a low-cost, prepaid debit card. 'It became clear that the immense amount of regulation that any new entity faces is a massive barrier to entry which protects the existing banks,' says Carne Ross, a diplomat and member of the Occupy group. US laws made it impossible to establish a national credit union open to any customer. 考虑占领华尔街，这场抗议运动正视银行业不公平的根深蒂固和对公共财政的依赖。在抗议活动之后，一群占领者试图在美国建立一个全国性信用合作社或银行，推出一张低成本的预付借记卡，但未能成功。占领者的一员、外交官兼占领团体成员卡恩·罗斯表示：“很明显，任何新实体面临的大量监管是一个巨大的准入壁垒，这保护了现有的银行。”美国法律使得建立一个对任何客户开放的全国性信用合作社成为不可能。
Mr Andreessen believes non-banks will manage to work around regulations. There may be something to this - it is striking that my energy supplier offers a higher rate of interest on deposits than my bank - but neither regulators nor the public will tolerate shadow retail banking for long if something goes wrong, as it tends to do. 安德里森先生相信非银行机构将设法规避监管。这可能有一定道理——令人惊讶的是，我的能源供应商提供的存款利率比我的银行高——但如果出现问题（而这种情况往往会发生），监管机构和公众都不会容忍影子零售银行业太久。
The biggest barrier to competition is that the core business of taking in deposits and keeping them safe is not very profitable in a low-interest world. Deloitte, the consultancy, estimates that UK banks make a 1.1 per cent loss on current account deposits at existing interest rates because they earn less on the cash while still bearing the costs of technology and branches. 竞争的最大障碍是，在低利率世界中，吸收存款并保管它们的核心业务并不十分有利可图。咨询公司德勤估计，根据现有利率，英国银行对活期存款亏损 1.1%，因为他们在现金上赚得更少，同时仍承担着技术和分支机构的成本。
A start-up bank that has no branches and spends less on patching up legacy software might do this more efficiently - and good luck to those that penetrate the regulatory thicket and try. But it is much less risky to attach a new service to the existing banking infrastructure, and it absorbs less capital. This is what most start-ups - and companies such as Apple and Google - are doing. They are not lending money, except through a banking partner. They offer services on top of the banking network - PhotoPay and WorldRemit, for example - or aggregate financial products provided by others, for example, Moneysupermarket. 一家没有分支机构并且在修补传统软件方面花费较少的初创银行可能会更有效地做到这一点 - 祝愿那些能够穿透监管丛林并尝试的人好运。但是，将新服务附加到现有银行基础设施上要冒的风险要小得多，并且吸收的资本也较少。这是大多数初创公司 - 以及苹果和谷歌等公司 - 正在做的事情。他们不借钱，除非通过银行合作伙伴。他们在银行网络之上提供服务 - 例如 PhotoPay 和 WorldRemit - 或者整合他人提供的金融产品，例如 Moneysupermarket。
Technology may eventually change the infrastructure of banking but it will not happen soon. Sean Park, founder of the advisory firm Anthemis, estimates that this 'is a long-term threat that will play out over decades, not months or years'. I will not hold my breath for Bitcoin to replace the central ledger of bank settlement, which dates from 17th-century goldsmith banks. Until then, Silicon Valley will compete at the edges, where banks make their best profits. It is not a bad compromise for them, or for customers. 技术可能最终会改变银行业的基础设施，但这不会很快发生。Anthemis 咨询公司创始人肖恩·帕克估计，这是一个长期威胁，将在几十年内逐渐显现，而不是几个月或几年内。我不指望比特币能够取代银行结算的中央账本，这个账本可以追溯到 17 世纪的金匠银行。在那之前，硅谷将在银行获利最多的边缘展开竞争。对他们或客户来说，这并不是一个坏的妥协。
Abridged 简化
Source: FT October 15, 2014 John Gapper 来源：FT 2014 年 10 月 15 日 约翰·加珀
Case study 12.4 案例研究 12.4
Global players' union urges football overhaul 全球球员工会敦促足球改革
The union representing professional footballers has turned to Brussels to overhaul the way the sport is run, arguing that the transfer window system hinders competition and cements the dominance of the game's richest clubs. FIFPro, which represents more than 65,000 professional footballers worldwide, said on Friday that it had filed a formal complaint against Fifa, world football's governing body, which is already reeling from a string of arrests in a bribery investigation launched by US authorities. 代表职业足球运动员的工会已经求助于布鲁塞尔，以改革体育运营方式，认为转会窗口制度阻碍了竞争，并巩固了游戏最富有俱乐部的主导地位。代表全球超过 65,000 名职业足球运动员的 FIFPro 周五表示，已正式向国际足球联合会 FIFA 提出正式投诉，后者已经在美国当局发起的一系列贿赂调查中受到打击。
The union's complaint argues that only the wealthiest clubs have the financial firepower to pay the huge transfer fees required to sign the best players and to prevail in often frenzied negotiations within restricted transfer windows. By lodging the complaint, FIFPro is accusing the national governing bodies that operate through Fifa of being anticompetitive. English Premier League clubs alone spent in the recent window, with Manchester United paying for Anthony Martial, a relatively untested 19 -year-old French striker. 工会的投诉认为，只有最富有的俱乐部才有财力支付巨额转会费，以签下最好的球员，并在有限的转会窗口内在通常激烈的谈判中取胜。通过提出投诉，FIFPro 指控通过国际足联运作的国家管理机构具有反竞争性。仅英超联赛俱乐部在最近的转会窗口中就花费了 ，曼联支付 签下了 19 岁的法国前锋安东尼·马蒂亚尔，一个相对未经检验的球员。
The European Commission confirmed it had received the complaint and would assess whether to issue charges. Privately, an EU official said Brussels had been exploring whether there were grounds for action against Fifa for several months. FIFPro's complaint was filed after talks with commission officials. FIFPro said it had sought to illustrate to the commission how a distorted market for players had ramifications for the wider economy. 欧洲委员会证实已收到该投诉，并将评估是否提出指控。私下里，一名欧盟官员表示，布鲁塞尔已经几个月来一直在探讨是否有理由对国际足联采取行动。FIFPro 的投诉是在与委员会官员会谈后提交的。FIFPro 表示，他们试图向委员会说明球员市场扭曲对更广泛经济的影响。
Jonas Baer-Hoffman, FIFPro policy director, said that by keeping some teams weak, the transfer system affected 'clubs' ability to be successful in other markets including broadcasting rights, merchandise and sponsorship'. He added that 'transfer fees represent a very, very high barrier to entry for clubs who are outside the dominant groupings'. FIFPro 政策总监乔纳斯·贝尔-霍夫曼表示，通过保持一些球队的弱势，转会系统影响了“俱乐部在其他市场（包括广播权、商品和赞助）取得成功的能力”。他补充说，“转会费代表了对那些处于主导集团之外的俱乐部来说非常非常高的进入壁垒”。
A study for the commission in 2013 found the total value of transfers in the EU swelled to in the 2010-2011 season from in 1994-1995. Transfer fees represent a very, very high barrier to entry for clubs who are outside the dominant groupings. The transfer window system is outlined in a 2001 agreement between the commission, Fifa and Uefa, European football's governing body. FIFPro argues this was based on the understanding there would be a 'solidarity mechanism' to ensure money trickled down to smaller clubs. But it also says this has not happened, meaning it is time to change the entire system. 2013 年委员会的一项研究发现，欧盟转会总价值从 1994-1995 赛季的 增长到了 2010-2011 赛季的 。转会费对于那些处于主导集团之外的俱乐部来说是一个非常非常高的进入壁垒。转会窗口系统概述在 2001 年委员会、国际足联和欧洲足球管理机构欧足联之间的协议中。FIFPro 认为，这是基于有一个“团结机制”来确保资金流向较小的俱乐部的理解。但它也表示这种情况并没有发生，这意味着是时候改变整个系统了。
As its complaint against Fifa has been levelled as an 'association of undertakings', by extension it relates to the national associations that make up Fifa and their constituent clubs. A formal complaint escalates a competition issue to a level where the commission is expected to draw a conclusion on whether it believes the market is being distorted. Big fines are possible in competition cases but FIFPro is mainly targeting an overhaul of football's commercial structure through a revision of the 2001 agreement. 由于其针对国际足球联合会的投诉被认定为“企业协会”，因此它涉及到组成国际足球联合会的国家协会及其成员俱乐部。正式投诉将竞争问题升级到一个层面，预计委员会将就其是否认为市场存在扭曲做出结论。在竞争案件中可能会面临巨额罚款，但 FIFPro 主要是通过修订 2001 年协议来瞄准足球商业结构的彻底改革。
Source: FT September 18, 2015 Christian Oliver 来源：FT 2015 年 9 月 18 日 Christian Oliver
12.8 Summary 12.8 总结
There are some barriers to entry over which neither incumbents nor entrants have direct control. Economies of scale can act as an entry barrier in two ways. First, there is an entry barrier if the minimum efficient scale (MES) of production is large relative to the total size of the market. Second, economies of scale can act as an entry barrier when average costs associated with a production level below the MES are substantially greater than average costs at the MES. Economies of scale present the potential entrant with a dilemma. Either the entrant accepts the risks associated with large-scale entry to avoid the average cost penalty, or the entrant enters at a smaller scale and absorbs the average cost penalty. 进入市场存在一些障碍，无论现有企业还是新进入者都无法直接控制。规模经济可以通过两种方式成为进入壁垒。首先，如果生产的最低效率规模（MES）相对于市场总规模较大，则存在进入壁垒。其次，当生产水平低于 MES 时的平均成本明显高于 MES 时的平均成本时，规模经济可以成为进入壁垒。规模经济给潜在的新进者带来两难选择。新进者要么接受与大规模进入相关的风险以避免平均成本惩罚，要么以较小规模进入并承担平均成本惩罚。
An incumbent has an absolute cost advantage over an entrant if the longrun average cost function of the entrant lies above that of the incumbent, and the entrant therefore faces a higher average cost at every level of output. An absolute cost advantage might arise in several ways. The incumbent might have access to a superior production process, hold patents or be party to trade secrets. 如果新进者的长期平均成本函数高于现有企业的成本函数，那么现有企业就具有绝对成本优势，因此新进者在任何产量水平上都面临更高的平均成本。绝对成本优势可能以几种方式出现。现有企业可能拥有更优越的生产流程，拥有专利或参与商业秘密。
The incumbent might have exclusive ownership or control over factor inputs, or access to cheaper sources of finance. Finally, the entrant might incur costs in the form of expensive advertising or marketing campaigns, in an effort to create a reputation or establish its own brand identities and brand loyalties. 现任者可能拥有独家所有权或控制要素输入，或者可以获得更便宜的融资来源。最后，新进入者可能会以昂贵的广告或营销活动形式产生成本，以努力建立声誉或确立自己的品牌身份和品牌忠诚度。
Other barriers to entry include: product differentiation in the form of customer loyalties to established brands and reputations of incumbents; switching costs; network externalities; legal barriers to entry; and geographic barriers, which create difficulties for foreign firms attempting to trade in the domestic market. 其他进入壁垒包括：产品差异化，即客户对已建立品牌和现任者声誉的忠诚度；转换成本；网络外部性；法律进入壁垒；以及地理壁垒，这为试图在国内市场交易的外国公司带来困难。
Entry-deterring strategies are barriers to entry created or raised by incumbents through their own actions. The extent to which it is possible for incumbents to adopt entry-deterring strategies is likely to depend on the degree of market power in the hands of the incumbent. Under a limit-pricing strategy, the incumbent seeks to prevent entry by charging the highest price possible without inviting entry. To do so, it exploits either an absolute cost advantage or an economies of scale advantage, in order to set a price such that if entry takes place, the entrant is unable to earn a normal profit. 进入阻挡策略是现有企业通过自身行动创造或提高的进入障碍。现有企业能够采用进入阻挡策略的程度可能取决于现有企业手中的市场力量程度。在限价策略下，现有企业试图通过收取尽可能高的价格来阻止进入而不引发进入。为此，它利用绝对成本优势或规模经济优势，以便设定价格，以便如果发生进入，新进入者无法获得正常利润。
A strategy of predatory pricing on the part of an incumbent involves cutting price in an attempt to force an entrant to withdraw from the market. When the entrant has withdrawn, the incumbent raises its price. The incumbent sacrifices profit and perhaps sustains losses in the short run to protect its market power in the long run. An incumbent faced with threatened entry might attempt to ward off the threat by convincing the potential entrant that it would implement a predatory pricing policy in the event that entry takes place. 现有企业采取的掠夺性定价策略涉及降低价格，试图迫使新进入者退出市场。当新进入者退出时，现有企业会提高价格。现有企业在短期内牺牲利润，甚至可能遭受损失，以保护其长期市场力量。面临潜在进入威胁的现有企业可能会试图通过说服潜在新进入者，如果发生进入，它将实施掠夺性定价政策来抵御威胁。
For many product types, a certain amount of product differentiation is quite natural, in view of basic product characteristics and consumer tastes. In some imperfectly competitive markets, however, incumbent firms may employ advertising or other types of marketing campaign to create or strengthen brand loyalties beyond what is natural to the market, raising the initial costs entrants will incur in order to establish a presence. In this case, product differentiation becomes a strategic entry barrier. Finally, it is suggested that incumbents may attempt to deter entry by deliberately increasing their sunk cost investment expenditure before entry takes place. The incumbent signals a commitment to fight entry by engaging the entrant in a price war. 对于许多产品类型来说，考虑到基本产品特性和消费者口味，一定程度的产品差异化是相当自然的。然而，在一些不完全竞争的市场中，现有企业可能会利用广告或其他类型的营销活动来创造或加强品牌忠诚度，超出市场自然水平，从而提高新进入者为建立存在而产生的初始成本。在这种情况下，产品差异化成为一种战略性的进入壁垒。最后，有人提出，现有企业可能会试图通过在进入之前故意增加其沉没成本投资支出来阻止进入。现有企业通过与新进入者进行价格战来表明他们打算抵制进入。
Contestable markets theory considers an industry comprising a small number of incumbent firms or a single incumbent, whose market power is constrained by the threat of potential entry. Even though the incumbents are few in number, and the industry appears to be highly concentrated, the threat of hit-and-run entry keeps prices close to the competitive level. A large number of competing firms is not a necessary condition for industry price and output to be set at the perfectly competitive level. Threatened competition from potential entrants may be sufficient to produce the same effect. Contestable markets theory breaks the direct link between the number and size distribution of sellers and the amount of discretion exercised by incumbents in determining their own prices. 有争议的市场理论认为，一个行业由少数现有公司或单一现有公司组成，其市场力量受到潜在进入的威胁的限制。即使现有公司数量不多，行业看起来高度集中，但被迅速进入的威胁使价格保持接近竞争水平。大量竞争公司并非行业价格和产出设定在完全竞争水平的必要条件。来自潜在进入者的竞争威胁可能足以产生相同的效果。有争议的市场理论打破了卖方数量和规模分布与现有公司在确定自己价格时行使的自由裁量之间的直接联系。
A more dynamic view of entry and market evolution over the long run regards entry as not an equilibrating mechanism, as assumed in the neoclassical theories of perfect and monopolistic competition, but rather as a disequilibrating force which, by changing and disrupting established market equilibria, plays a central role in shaping the evolution of industry structure in the long run. 长期内对进入和市场演变的更动态观点认为，进入不是一个均衡机制，如新古典理论中对完全竞争和垄断竞争的假设所认为的那样，而是一种扰乱力量，通过改变和破坏已建立的市场均衡，在长期内在塑造行业结构演变中发挥着核心作用。
Most of the empirical evidence on the determinants of entry in manufacturing confirms that high industry profitability and growth are effective stimulants to entry. There is also some empirical evidence that, in accordance with the theory, entry barriers resulting from economies of scale, heavy capital requirements, high advertising or research and development intensities, high levels of business risk and high levels of industry concentration are effective in slowing the rate at which entry takes place. 大多数关于制造业进入决定因素的经验证据证实，高行业利润和增长是促进进入的有效刺激因素。也有一些经验证据表明，与理论相一致，由规模经济、巨额资本需求、高广告或研发强度、高商业风险和高行业集中度导致的进入壁垒有效地减缓了进入速度。
Discussion questions 讨论问题
With reference to Case Study 12.1, identify barriers to entry to the UK retail banking industry. 参考案例研究 12.1，确定进入英国零售银行业的壁垒。
With reference to Case study 12.2, explain how switching bank accounts, tying and bundling financial products can act as an entry barrier. 参考案例 12.2，解释如何切换银行账户、捆绑和捆绑金融产品可以作为进入壁垒。
With reference to Case study 1.2, assess the extent to which the application of technology to retail banking by some new firms is a serious threat to incumbent banks. 参考案例 1.2，评估一些新公司将技术应用于零售银行业对现有银行构成严重威胁的程度。
With reference to Case study 12.4, identify the barriers faced by football teams outside the dominant groups. 参考案例 12.4，识别足球队在主导群体之外面临的障碍。
Why might the height of entry barriers to a particular industry be measured in practice? 为什么在实践中可能会测量特定行业的准入壁垒高度？
To what extent does the theory of limit pricing provide a useful contribution to the theory of entry deterrence? 极限定价理论在准入威慑理论中提供了多大程度的有用贡献？
Is limit pricing preferable to monopoly pricing on social welfare criteria? 从社会福利标准来看，极限定价是否优于垄断定价？
What factors are likely to influence the credibility of a threat by an incumbent to engage an entrant in predatory competition, in the event that entry takes place? 什么因素可能影响现有企业对新进入者进行掠夺性竞争威胁的可信度，如果进入发生了？
Explain how an incumbent might attempt to deter entry by increasing its own sunk cost investment. 解释现有企业如何通过增加自身沉没成本投资来试图阻止进入。
What factors are relevant for a firm in deciding whether to be a pioneer in a new market, or to enter an established market at a later stage? 一个公司在决定是成为新市场的先行者，还是在后期进入已建立的市场时，哪些因素是相关的？
Explain the theory of contestable markets. To what extent does the empirical evidence justify the idea that potential competition is an important influence on pricing behaviour? 解释可争夺市场理论。实证证据在多大程度上证明潜在竞争对定价行为有重要影响？
Examine the role of entry and exit in determining the evolution of industry structure. 研究进入和退出在决定产业结构演变中的作用。
According to the empirical evidence, what are the most commonly used entry-deterring strategies adopted by incumbent firms in new and established product markets? 根据实证证据，现有公司在新产品市场和成熟产品市场中采用的最常见的阻止进入策略是什么？
Further reading 进一步阅读
Bain, J.S. (1956) Barriers to New Competition. Cambridge, MA: Harvard University Press. 贝恩，J.S.（1956）新竞争的障碍。剑桥，马萨诸塞州：哈佛大学出版社。
Baumol, W.J., Panzer, J. and Willig, R.D. (1982) Contestable Markets and the Theory of Industry Structure. New York: Harcourt Brace Jovanovich. 鲍默尔，W.J.，潘泽，J.和威利格，R.D.（1982）可竞争市场和产业结构理论。纽约：哈考特布雷斯乔万诺维奇。
Berry, S. and Reiss, P. (2007) Empirical models of entry and market structure, in Armstrong, M. and Porter, R. (eds) Handbook of Industrial Organization, vol. 3. Amsterdam: Elsevier. Berry, S.和 Reiss, P. (2007)进入和市场结构的实证模型,见 Armstrong, M.和 Porter, R. (编)《产业组织手册》第 3 卷. 阿姆斯特丹:爱思唯尔.
