A well established belief both in the game-theoretic IO and in policy debates is that market concentration facilitates collusion. We show that this piece of conventional wisdom relies upon the assumption of profit-seeking behaviour, for it may be reversed when firms pursue other plausible goals....

A well established belief both in the game-theoretic IO and in policy debates is that market concentration facilitates collusion. We show that this piece of conventional wisdom relies upon the assumption of profit-seeking behaviour, for it may be reversed when firms pursue other plausible goals....

This paper provides a simple model of repeated extortion. In particular, we ask whether corrupt government officials' ex post opportunism to demand more once entrepreneurs have made sunk investments entails further distortion in resource allocations. We show that the inability of government...

I study the properties of optimal long-term contracts in an environment in which the agent.s type evolves stochastically over time. The model stylizes a buyer-seller relationship but the results apply quite naturally to many contractual situations including regulation and optimal...