Delipalla and O'Donnell (2001) contains a formula for the incidence of specific and ad valorem taxes in a conjectural variation oligopoly model with potentially asymmetric firms. The formula is incorrect. We derive the correct formula and provide a discussion of the error and its implications...

What institutions can sustain cooperation in groups of strangers? Here we study the role of monetary systems. In an experiment, subjects sometimes needed help and sometimes could incur a cost to help an anonymous counterpart. In the absence of money, the intertemporal exchange of help, which...

Experimental evidence has accumulated highlighting the limitations of formal and explicit contracts in certain situations, and has identified environments in which informal and implicit contracts are more efficient. This paper documents the superior performance of explicit over implicit...

Social life offers innumerable instances in which trust decisions involve multiple agents. Of particular interest is the case when a breach of trust is not profitable if carried out in isolation, but requires an agreement among agents. In such situations the pattern of behaviors is richer than...

We study cooperation in economies of indefinite duration. Participants faced a sequence of prisonerʼs dilemmas with anonymous opponents. We identify and characterize the strategies employed at the individual level. We report that (i) grim trigger does not describe well individual play and there...

While peer punishment has been shown to increase group cooperation, there is open debate on how cooperative norms can emerge and on what motives drive individuals to punish. In a public good experiment we compared alternative punishment institutions and found (1) higher cooperation levels under...

We study the emergence of norms of cooperation in experimental economies populated by strangers interacting indefinitely. Can these economies achieve full efficiency even without formal enforcement institutions? Which institutions for monitoring and enforcement facilitate cooperation? Finally,...