We find an "inverse found money effect" in two-person public good experiments in which individuals earning their endowments contribute more and engage in "altruistic conditional cooperation" when they are matched with those whose endowment is provided by the experimenters.

We report the results of experiments designed to investigate the effects of random public revelation of individual choices on voluntary contributions to a public good. Varying the number of subjects whose contributions are made public, we find that public revelation always leads to higher...