Sorting into Incentives for Prosocial Behavior

We study incentivized voluntary contributions to charitable activities. Motivated by the market for blood donations in Germany, we consider a setting where different incentives coexist and agents can choose to donate without receiving monetary compensation. We use a model that interacts image concerns of agents with intrinsic and extrinsic incentives to donate. Laboratory results show that a collection system where compensation can be turned down can improve the efficiency of collection. Image effects and incentive effects do not crowd each other out. A significant share of donors turn down compensation. Heterogeneity in treatment effects suggests gender-specific preferences over signaling