Risk and reliability dominate water supply discussions in the arid western United States due to increasing demand and finite, weather-dependent supply. Water markets have evolved in this region so agencies could meet this growing demand. In a few instances, water agencies turned to contractual...

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 United States than anywhere else.