Some experimental evidence regarding collusion

A study examined experimentally generated examples of overt and tacit collusion. The experimental environment was based on a model developed by Morrison (1979), which accommodates any number of rivals and has 3 solutions: zero profit, Cournot-Nash, and collusion. The experiments involved subjects serving as chief executive officers of rival firms. Overt collusion was observed in a series of experiments involving masters of business administration (MBA) students at Indiana University. The interviews and experiments presented a variety of motives and actions. Tacit collusion experiments were conducted with 4 MBA students at the University of Notre Dame. No indication of tacit collusion was found with 3 or more rivals. However, a variety of tacit collusions was observed with 2 rivals and high markups.