Contribution to a Public Good Under Uncertainty : Anexperimental Inquiry

Using data from a laboratory experiment, I study how contributions to a publicgood are affected when subjects face uncertainty regarding the benefit from thepublic good. In addition, I contrast the case when subjects differ in the benefitthey get from a public good with when the benefit is homogeneous. I investigatewhether heterogeneity in benefits affects contributions differently under certaintyand uncertainty. I elicit conditional contribution behavior to test if my results arerobust to changes in subjects’ beliefs regarding the contributions of others. I findthat contributions under uncertainty are lower than under certainty. Heterogeneityin benefits also decreases contributions, but this effect is weaker under uncertaintythan certainty. Uncertainty and heterogeneity do not affect conditional contributions