Essays in Honor of Hannu Nurmi Homo Oeconomicus 26(3/4): 455–469 • (2009) www.accedoverlag.d e Voting and Power

Abstract The credibility of voting power theory is undermined by the lack of clarity about the precise specification of the underlying collective decision-making situation. We propose a basic distinction between two scenarios in which a com-mittee can make decisions under a voting rule. In a ‘take-it-or-leave-it ’ scenario the committee has only the choice of accepting or rejecting by vote proposals submitted from outside, while in a ‘bargaining ’ committee negotiation is feasible and the voting rule conditions it by imposing which groups of voters can enforce any agreement. From these two points of view we reinterpret and critically review the foundations and normative recommendations of voting power theory