Why Roll Calls? A Model of Position-Taking in Legislative Voting and Elections

We develop a rationale for roll call voting and position-taking in legislatures using a formal model of legislative vote buying and elections. In our model, citizens and an interest group are motivated by policy, while legislators are motivated by holding office. The group may attempt to buy legislators' votes by offering contracts based on their votes. If citizens cannot condition their reelection votes on legislators` roll calls, then in equilibrium the group will buy its ideal policy and most legislators are voted out of office. This is because the group's contract can promise a nonnegligible payment to each legislator only in the event that her vote is pivotal, but also force no legislator to be pivotal. If citizens can condition their votes on legislators' roll calls, then policies are more moderate and more legislators are reelected. Thus an endogenous preference for position-taking arises in a legislature with public roll calls, and both legislators and citizens will prefer such open proceedings ex ante. We explore extensions of the basic model and find some circumstances where the incentives to have open proceedings are weaker