This paper examines the relationship between variations in group size and “free-riding” behavior in the voluntary provision of public goods. We examine experimentally two pertinent concepts: the marginal return to an individual from contributions to the public good, and the actual number of members in the group. Our results strongly support a hypothesis that increasing group size leads to a reduction in allocative efficiency when accompanied by a decrease in marginal return from the public good (as from crowding or an association of large groups with imperceptibility of marginal benefits). Our results do not support a pure numbers-in-the-group effect.

Daniel H. Hill, Deborah A. Ott, Lester D. Taylor, James M. Walker, Incentive Payments in Time-of-Day Electricity Pricing Experiments: The Arizona Experience, The Review of Economics and Statistics, Vol. 65, No. 1 (Feb., 1983), pp. 59-65

This paper reports the results of controlled experiments designed to test the Harris‐Raviv generalization of the Vickrey theory of bidding in multiple unit discriminative auctions. The paper also discusses further development of the theory—in a way suggested by the experimental results—to include bidders with distinct risk preferences.