Evidence of gender differences in cooperation in social dilemmas is inconclusive. This paper experimentally elicits unconditional contributions, a contribution vector (cooperative preferences), and beliefs about the level of others' contributions in variants of the public goods game. We show...

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...