We report on an experiment in which subjects choose actions in strategic games with either strategic complements or substitutes against a granny, a game theorist or ther subjects. The games are selected in order to test predictions on the comparative statics of equilibrium with respect to...

The realization of market transactions often depends on decisions in groups in which members are anonymous and cannot communicate, but have interrelated outcomes. In a comprehensive study, we investigated the interaction of group effects, strategic effects and endowment effects in different...