We systematically investigate the relationship between the number of firms in a market and tacit collusion by means of a meta-analysis of the literature on oligopoly experiments as well as two of our own experiments with a total of 368 participants. We show that the degree of tacit collusion decreases strictly with the number of competitors in industries with two, three and four firms. Although previous literature could not affirm that triopolies are more collusive than quadropolies, we provide evidence for this fact for symmetric and asymmetric firms under Bertrand and Cournot competition. † Authors' affiliations:
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.