Capacity, Output, and Sequential Entry
建立了一个动态进入模型，分析在位企业如何通过产量或产能策略阻止潜在进入者，并检验了Sylos假设和过剩产能假设在理性行为下是否成立。
Two crucial assumptions frequently made in industrial organization are that an established firm deters entry either by a constant high output (the Sylos Postulate) or by high excess capacity (the Excess Capacity Hypothesis). These assumptions may be an accurate description of the observed conduct of firms in some industries. However, when the rules of the post-entry game are clearly specified, the optimal output and investment strategies of an established firm may depart considerably from these behavioral assumptions. Because of this possible inconsistency with rational behavior, any conclusions about the formation of industry based upon either assumption are highly suspect. What is more, these assumptions avoid the main issue of whether entry deterrence is worthwhile at all. This paper presents a dynamic model of entry in which established firms pursue a Cournot Nash (alternatively Stackelberg) strategy toward a potential entrant. The entrant behaves in Cournot-Nash fashion and chooses output on the basis of expected postentry profits at the equilibrium of the post-entry game. Within this framework, a constant output entry-deterring strategy would involve maintenance of an entry-deterring output level before and after entry is threatened. An excess capacity entry-deterring strategy would involve holding excess capacity at an entry-deterring level and increasing output to that level after entry is threatened. Special conditions are presented under which the Sylos Postulate or the Excess Capacity Hypothesis will accurately describe optimal entry-deterring strategies. In addition, special conditions are examined under which the established firm maintains a constant output or holds pre-entry excess capacity when large-scale entry does in fact take place. The analysis shows that in general, established firm reactions to entry are quite different from these special cases. The Sylos Postulate (see Joseph Bain; Paolo Sylos-Labini; Franco Modigliani, 1958) asserts not only that potential entrants expect established firms to maintain their output constant as entry occurs, but that established firms keep output constant at a level that deters entry whether or not it is profitable to do so. Hailed as a welcome major breakthrough on the oligopoly front (Modigliani, 1958) the Sylos Postulate underlies many papers in the large theoretical and empirical literature on limit pricing.' Yet the Sylos Postulate ignores both the strategic interaction between firms and the dynamic aspects of entry.2 Unless the established firm's monopoly output exceeds the entrydeterring level, the established firm with a general cost function able to choose an entry-deterring output level will instead always desire a lower output level before entry. For the special case where capacity is an upper bound on output and the established firm is a Stackelberg leader in the post-entry game,