This paper surveys some of the strategic aspects that emerge if players fight in an alliance against an enemy. The survey includes the free-rider problem and the hold-up problem that emerges in the baseline model, the role of supermodularity in alliance members' effort contributions, the role of...

Contests between groups are plagued by intra-group externalities (freeriding). Yet, costless incentive schemes that entirely avoid free-riding within a group might not be desirable, neither individually nor socially. In contests among two groups, a relatively weak (i.e., small or unproductive)...

We study the role of information exchange through alliances in a framework with contestants who have binding budget limits and know their own budget limit but are incompletely informed about other contestants' budget limits. First, we solve for the Bayesian Nash equilibrium. Then we consider the...

We study an all-pay contest with multiple identical prizes (lifeboat seats). Prizes are partitioned into subsets of prizes (lifeboats). Players play a two-stage game. First, each player chooses an element of the partition (a lifeboat). Then each player competes for a prize in the subset chosen...

Usually, groups increase their productivity by the specialization of their group members. In these cases, group output is no longer simply a sum of individual outputs. We analyze contests with group-specific public goods that allow for different degrees of complementarity between group...

The present paper analyzes situations in which groups compete for rents. A major result in the literature has been that there are both cases where larger groups have advantages and cases where they have disadvantages. The paper provides two intuitive criteria which for groups with homogenous...

Reforms often occur in waves, seemingly cascading from country to country. We argue that such reform waves may be driven by informational spillovers: uncertainty about the outcome of reform is reduced by learning from the experience of similar countries. We motivate this hypothesis with a simple...