One lingering puzzle is why voluntary contributions to public goods decline over time in experimental and real-world settings. We show that the decline of cooperation is driven by individual preferences for imperfect conditional cooperation. Many people's desire to contribute less than others,...

Psychological game theory can provide a rational choice explanation of framing effects; frames influence beliefs, and beliefs influence motivations. We explain this point theoretically, and explore its empirical relevance experimentally. In a 2×2-factorial framing design of one-shot public good...

We report evidence from public goods experiments with and without punishment which we conducted in Russia with 566 urban and rural participants of young and mature age cohorts. Russia is interesting for studying voluntary cooperation because of its long history of collectivism, and a huge...

This paper uses a novel experimental design to study the contagion of pro- and antisocial behavior and the role of social proximity among peers. Across systematic variations thereof, we find that anti-social behavior is generally more contagious than pro-social behavior. Surprisingly, we also...

We study escalation and aggression in an experimental first-strike game in which two participants play multiple rounds of a money-earning task. In each round, both players can spend money to accumulate weapons. The player with more weapons can spend money to strike against the other player,...