This is a guest post from Alessandra Casella, an economics professor at Columbia University, and Sébastien Turban, an economics Ph.D. candidate there. Alessandra Casella’s book on Storable Votes is available here. Sébastien Turban joined the project when the manuscript was already written but contributed substantially to its final shape.
The Senate has become less efficient in passing significant legislation. The public is upset at the gridlock in Congress and wants politicians to cooperate. Political commentators believe that significant responsibility for such malfunctioning rests with the Senate filibuster. Sarah Binder, Greg Koger, Greg Wawro and Eric Shickler on The Monkey Cage and in their respective books, Barbara Sinclair and Ezra Klein in The Washington Post, have all discussed the desirability of possible reforms in detail over the last years.
It seems to us that the debate on the filibuster points to a more general question on the appropriate protection of the minority. The filibuster exists to protect the minority party, and indeed taming the tyranny of the majority is essential to the legitimacy of democracy. But the filibuster does so very inefficiently: it amounts to a super-majority rule, with its built-in bias towards the status-quo.
The problem is that sanctioning simple majority rule, treating all votes and voters identically, and protecting the minority seem mutually incompatible goals. Using storable votes, this need not be the case. Suppose that a group of voters were asked to pass or fail a number of independent proposals. Each proposal is decided by majority vote, and each voter is granted the same number of votes. However, subject to the overall budget of votes, each voter is allowed to decide how many votes to cast on any individual proposal. With ten proposals and ten votes, an individual voter could cast one vote on each proposal, several votes on some of the proposal and none on the others, or all ten votes on one proposal. The voter will cast more votes on the proposals he feels more strongly about, increasing his probability of winning when it matters. Storable votes (1) equip every voter with the same number of votes; (2) allow voters to cast more votes on decisions that matter to them most, and (3) empower the minority to prevail occasionally.
The central idea is the possibility of shifting one’s own votes from one contest to another, of storing votes not spent on decisions that are low priorities for use on decisions that matter more. Voters’ behavior thus reflects truthfully the relative intensities of their preferences over issues. By cumulating votes on one or few of the proposals, a cohesive minority can win when its preferences are most intense. And because the majority generally holds more votes, it is in a position to overrule the minority if it cares to do so: the minority can win only those issues over which its strength of preferences is high and the majority’s preference intensity is weak. Note again that all voters are treated equally: all individuals are granted the same number of votes and all votes are equal.
The mechanism has been tested by Alessandra Casella and her co-authors (Shuky Ehrenberg, Andrew Gelman, Thomas Palfrey, Raymond Riezman, Jie Shen) in laboratory experiments, and in one natural setting. The results confirmed the intuition: the minority wins occasionally, but only when the costs to the majority are small. The conclusion continues to hold when one party is granted some limited agenda power.
Storable votes resemble cumulative voting, a semi-proportional electoral system used in local jurisdictions and in corporations to facilitate the election of minority candidates. Storable votes, however, are a voting system for decision-making, as opposed to an electoral system, and in this they differ not only from cumulative voting but also from most other well-known voting rules: for example, Borda rule, Approval Voting, Range Voting, or Single Transferable Vote. In an electoral system, all candidates are compared, and a fixed number of winners is elected. With storable votes, each proposal is compared only to its own rejection, and all could in theory pass, or all could fail. Nor do storable votes resemble vote-trading: voters can shift their individual votes across different proposals but are not allowed to trade votes interpersonally. In fact, the system discourages informal exchanges of favors: if not cast, a vote can be used over a different decision, and because it preserves its value, spending it to satisfy others’ requests is costly, even in exchange for promises of future favors.
In principle, storable votes could be implemented easily: they can have large effects, but are a reasonably minor deviation from simple majority voting. In the case of the filibuster, it is tempting to think, for example, that storable votes could help to address the increasing delays in confirming nominations. Consider the following procedure. At fixed intervals of time, the Senate is presented with a list of nominees, each nominated for a specific position, and each senator is granted a number of votes equal to the number of names on the list. A vote is then called on each nominee. A senator can cast as many of his total votes as he wishes in his preferred direction (for or against the nominee), distributing the number of votes at the senator’s disposal only over the specified set of nominees. The nominee is confirmed if a simple majority of votes cast on his name are in favor. New votes are assigned whenever a new list is voted upon.
Much of the scheme’s possible success would depend on the details of its rules: How frequently will the lists be presented? Should all nominations be treated equally? We do not want to argue here that storable votes are ready for immediate implementation. Rather, we want to suggest a potential new direction for solving gridlock in polarized environments.
P.S. from Andrew Gelman: Many commenters below suggest potential problems with storable votes. These are all worth looking into, but let’s not forget that our current system is a storable votes system with 1 fixed vote on each issue and 0 storable votes. Casella would keep the fixed vote; the only change is to increase the number of storable votes.