Market structure, tariff lobbying and the free-rider problem

The effect of changes in industry structure on the ability to maintain a co operative level of tariff lobbying are analyzed in a repeated game setting in which a simple trigger strategy is the enforcement mechanism. The diffic ulty of maintaining cooperation is identified with the minimum discount fac tor necessary for the maintenance of cooperation. Factors which increase th is critical value of the discount parameter are said to make cooperation mo re difficult. Some changes in industry structure which reduce measured conc entration have ambiguous effects, while others may make cooperation among a given group of firms more likely.