Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We report an experiment comparing sequential and simultaneous contributions to a public good in a quasi-linear two-person setting. In one parameterization we find that overall provision is lower under sequential than simultaneous contributions, as predicted, but the distribution of contributions is not as extreme as predicted and first movers do not attain their predicted first-mover advantage. In another parameterization we again find that the distribution of contributions is not as predicted when the first mover is predicted to free ride, but we find strong support for equilibrium predictions when the second mover is predicted to free ride. These results can be explained by second movers' willingness to punish first movers who free ride, and unwillingness to reward first movers who contribute.