Voting on Majority Rules

Abstract

Political economy models usually take as given the rules which govern the political decision making, with the simple majority rule being the most popular model. In this paper, we develop a simple yet powerful positive model where the majority rule governing future elections is itself chosen in an election. We observe a large variety of majority rules governing elections in the real world. On the one side, referenda are usually decided by a simple majority. At the other extreme, many international organizations require unanimity in votes among the member states. In the European Union’s council of ministers, some proposals require only a simple majority, some a supermajority of about 71% (62 votes out of 87) and some require unanimous consent. 1 Explicit supermajorities 2 are required in most countries for a change of the constitution, but in some U.S. states also for a tax raise. Even more important could be what we might call implicit supermajorities: in parliamentary systems with a strong committee organization, a legislative proposal usually needs the support of both the respective committee and the house. In parliamentary systems with two chambers, certain legislative proposals need the support of both chambers. 3 Previous rationalizations of qualified majority rules focus on the problem of Condorcet cycles under simple majority rule in n-dimensional elections and on commitment problems; see our literature review below. Our model presents a new rationale for rules requiring qualified majorities in elections. We analyse an overlapping generations model of voting on reform opportunities, which we model as similar to investment projects: at first, there is a cost and then there are benefits. Since voters have a finite lifetime, old voters will be less keen on reforms