Casella Alessandra author Columbia University. Economics Palfrey Thomas author Turban Sebastien author Columbia University. Economics Columbia University. Economics originator contributor text Working papers New York Department of Economics, Columbia University 2012 Two groups of voters of known sizes disagree over a single binary decision to be taken by simple majority. Individuals have different, privately observed intensities of preferences and before voting can buy or sell votes among themselves for money. We study the implication of such trading for outcomes and welfare when trades are coordinated by the two group leaders and when they take place anonymously in a competitive market. The theory has strong predictions. In both cases, trading falls short of full efficiency, but for opposite reasons: with group leaders, the minority wins too rarely; with market trades, the minority wins too often. As a result, with group leaders, vote trading improves over no-trade; with market trades, vote trading can be welfare reducing. Although the experimental data show evidence of overpricing,these predictions are satisfied by all experimental sessions. Economics 1213-01 http://hdl.handle.net/10022/AC:P:15387 English NNC NNC 2012-12-06 11:36:37 -0500 2012-12-06 12:13:41 -0500 9390 eng