Bribing voters

We show how an outside party offering incentives to voters can manipulate at no cost collective decisions made through voting. Under influence, these decisions can become inefficient. Therefore, the market for policies may be more likely to fail than the markets for goods, because (democratic) politics involves influence and collective decisions to a greater extent than markets for goods do. We develop and use a model to analyze different incentive schemes, credibility situations, and payoff and information structures. We discuss implications for the efficiency of democracy, voting, lobbying, committee decision making, and legislatures.