Buying supermajorities in the lab

Many decisions taken in legislatures or committees are subject to lobbying efforts. A seminal contribution the literature on vote-buying is legislative-lobbying model pioneered by Groseclose and Snyder (1996), which predicts that lobbies will optimally form supermajorities many cases. Providing first empirical assessment of this prominent model, we test its central predictions laboratory. While assumes sequential moves, relax assumption additional treatments with simultaneous moves. We find buy as predicted theory. Our results also provide supporting evidence for most comparative statics legislative respect legislators' preferences lobbies' willingness-to-pay. these carry over simultaneous-move set-up but predictive power declines.