Risk in payoff-equivalent appropriation and provision games

•Two types of exogenous probabilistic risk are examined, probabilistic individual-fund and group-fund returns.•Cooperation levels in decision situations in the appropriation game type are not significantly affected by either type of risk.•Cooperation levels in decision situations in the provision game increase with a probabilistic individual-fund return.•A probabilistic group-fund return does not significantly affect cooperation levels in the provision game.

Probabilistic risk is examined within appropriation and provision games. Using a menu design, subjects make decisions in multiple one-shot situations where the individual return or the group return is a random variable. Adding risk over the benefits of cooperation is found to significantly affect subjects' decisions only in situations in the provision game type where the individual return is probabilistic. In those decision situations, cooperation increases.