Laboratory elections with endogenous turnout: proportional representation versus majoritarian rule

I investigate the impact of proportional representation (PR) and majoritarian rule (MR) on voter turnout and minority representation using theory and experiments. Numerous empirical studies have compared turnout across PR and MR. However, the empirical evidence is mixed. I show theoretically and experimentally that the comparison of turnout across PR and MR depends on the size of the minority but the empirical papers on the topic do not control for it. I also show that, in both theory and data, PR improves minority representation at a minute cost to efficiency if the size of the minority is sufficiently large. However, the representation of a small minority does not show a remarkable improvement under PR, unlike what the theory predicts. I conjecture that, under PR, there is a discouragement effect for the small minority because the PR system that I employ has an election threshold. As a result, the impact of the voting system on representation may be sensitive to both the size of the minority and the degree of proportionality. Copyright Economic Science Association 2015