Preference Uncertainty, Voter Participation and Electoral Efficiency: An Experimental Study

We experimentally study the impact of preference uncertainty on voter turnout and electoral efficiency in a participation game. We find higher participation rates when the electorate is informed about the level of support for various candidates than when group sizes remain uncertain. Moreover, despite higher free riding incentives majorities win more often than minorities. In aggregate, whether or not group sizes are known hardly affects welfare. We also distinguish between allied and floating voters and our data show that the lower turnout under uncertainty can be attributed to floating voters participating less. Finally, our results match better the predictions by quantal response (logit) equilibria than by (Bayesian-) Nash equilibria.