Vote Trading in Power-Sharing Systems: A Laboratory Investigation
通过实验室实验，研究了权力分享制度和多数决制度中选票交易对选民福利的影响，发现权力分享制度下选票交易能提升总体福利，但多数决制度下则不然，且部分选民在权力分享制度中也会受损。
Abstract Vote trading in power-sharing systems—i.e., systems in which a voter’s utility with respect to the election’s outcome is proportional to the vote share of her favourite party—is, in theory, welfare improving. However, trading votes for money in majoritarian systems may have detrimental welfare effects, especially when voters’ preference intensities are similar (Casella et al., 2012). We use a laboratory experiment to test the effect of vote trading in each of these popular electoral systems on voter welfare and find strong evidence in support of the above intuitions: vote trading in power-sharing systems boosts aggregate welfare across all considered specifications, but it is not welfare improving in majoritarian systems. Importantly, and contrary to theoretical predictions, a substantial share of subjects consistently loses from vote trading even in power-sharing systems, indicating that its welfare effects are not unambiguous.