Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper tests the widely accepted hypothesis that, when a pure public good is voluntarily provided, incentives to free ride increase with the number of individuals consuming the good. Specifically, the author uses unique data on the number of listeners and contributors to public radio to test two hypotheses. First he tests whether the proportion of contributors falls as group size increases and, second, the author tests whether contributions per contributor falls as group size increases. He finds that increases in group size result in significantly more free riding. However, the author also finds that group size has no effect on contributions per contributor. Copyright 1998 by Kluwer Academic Publishers