We show that a combination of temporariness and spending pressure is intrinsic to the aid relationship. In our analysis, recipients rationally discount the pronouncements of donors about the duration of their commitments because in equilibrium they know that some donors will honor those...

In experimental games, many subjects cooperate contrary to their material interest and they do that in a reciprocal manner. In addition, many subjects punish those others who behave unkindly, and previous history usually influences subjects’ choices. We propose a simple game-theoretical model...