When the repeated prisoner's dilemma setup is generalized to allow for a unilateral breakup, maximal efficiency in equilibrium remains an open question. With restrictions of simple symmetry with eternal mutual cooperation, defection, or (matched) alternation on the equilibrium path, we describe...

Since Mancur Olson's “Logic of collective action” it is common conviction in social sciences that in large groups the prospects of a successful organization of collective actions are rather bad. Following Olson's logic, the impact of an individual's costly contribution becomes smaller if the...