Is There a Free-Rider Problem in Lobbying? Endogenous Tariffs, Trigger Strategies, and the number of Firms
通过重复关税游说博弈模型，分析企业数量增加时维持合作的能力，发现标准直觉（企业越多越难合作）并不普遍成立，临界贴现因子不一定随企业数量上升，且无限企业时仍可能维持合作。
There are two reasons we expect moreconcentrated industries to have advantages over less-concentrated industries in playing the lobbying game.' One is that in a noncooperative setting, as the number firms rises, we expect the free-rider problem to become worse (this is the finding of Rodrik, 1986). The second is that we expect that the ability to maintain a cooperative outcome deteriorates as the number of firms in the industry rises. [The classic reference is Mancur Olson (1965); also, see Russell Hardin (1982) and Todd Sandler (1992) among others.] In contrast with the second intuition, this paper shows that there is no general presumption that maintaining cooperation becomes more difficult as the number of firms in the industry rises. The ability of an industry to overcome the free-rider problem is analyzed in a re-peated tariff lobbying game where cooperation may be maintained through the use of a simple trigger strategy.2 The difficulty of maintaining cooperation is measured by the critical value of the discount parameter. All values above this critical value are consistent with cooperation, and all values below the critical value imply that cheating will prevent maintenance of the cooperative outcome. There is no presumption that this critical value rises with the number of firms. A separate, but related, question involves asymptotic results. Standard intuition suggests that as industry structure approaches perfect competition, it becomes impossible to maintain cooperation. In the context of this paper, this intuition corresponds to the critical value of the discount factor converging to I as the number of firms increases to infinity. In the general case it is shown that the critical value of the discount parameter converges to a value less than 1 in the limit as the number of firms becomes arbitrarily large. If the actual discount parameter lies above this value, then cooperation may be maintained even with an infinite number of firms. Though the framework here is quite simple, it provides results which contrast sharply to our standard intuition about how industry structure affects the ability to maintain cooperation.' There are two ways to interpret the results of this paper. One is to assert that standard intuition is wrong, and that there is, in fact, no presumption that maintaining cooperation becomes more difficult as the number