'Until not much more than 20 years ago, economists frequently lamented the fact that they were limited in their empirical analyses to statistical assessments of market behavior, because controlled economic experiments were (thought to be) infeasible, unethical, or both. Much has changed in the...

This paper studies the effect of introducing costly partner selection for the voluntary contribution to a public good. Subjects participate in six sequences of five rounds of a twoperson public good game in partner design. At the end of each sequence, subjects can select a new partner out of six...

We show in a public goods experiment on three continents that conditional cooperation is a universal behavioral regularity. Yet, the number of conditional cooperators and the extent of conditional cooperation are much higher in the U.S.A. than anywhere else. -- conditional cooperation ; public...