In many contest situations, such as R&D competition and rent seeking, participants’ costs are private information. We report the results of an experimental study of bidding in contests under different information and symmetry conditions about players’ costs of effort. The theory predicts...

We study how aggregate effort exerted in contests between groups of heterogeneous players depends on the sorting of players into groups. We show that the optimal sorting depends on the curvature of the effort cost function. From the perspective of a contest organizer whose objective is to...