The American Medical Political Action Committee: Which senators get the money and why?

Previous research has heightened the debate over what motivates the America n Medical Political Action Committee (AMPAC), the campaign financing arm of the American Medical Association (AMA). Analyses of roll call votes typica lly assume that vote-buying is the reason AMPAC contributes to members of C ongress, a hypothesis consistent with the theory of economic regulation, bu t one that has seldom been tested empirically.