Strategic behavior and learning in repeated voluntary contribution experiments

Voluntary contribution experiments systematically find that contributions decline over time. We use a two-stage voluntary contribution game to investigate whether this decrease is caused by learning or strategic behavior. Using a strategy method we find a robust pattern of declining contributions: contributions in stage 2 are 45 percent lower than in stage 1. Repeating the game five times we find that experience generates a smaller decline in contributions: stage 1 contributions decrease by around 7 percent per game. Finally we find no significant differences between the strategy and direct-response method, which suggests that our results help explain behavior in the latter.