Steven Brams
Professor of Politics, New York University
04:17

Better Voting Through Mathematics?

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The theoretical models Steven Brams constructs could help you make better strategic decisions at the polls.

Steven Brams

Steven Brams is a Professor of Politics at New York University. He graduated in 1962 from the Massachusetts Institute of Technology and received his Ph.D. in 1966 from Northwestern. His primary research interests include game theory and its applications, particularly in political science and international relations, and social choice theory, particularly as applied to voting and elections. He is one of the independent discoverers of approval voting and a co-discoverer of the first envy-free solution to the n-person cake cutting problem. Brams was a Guggenheim Fellow from 1986 to 1987 and is a member of the American Association for Advancement of Science.

Transcript

Question: Do you study real-world elections or theoretical models of elections?

Steven Brams: It’s some of both. We try to construct theoretical models that represent real life situations, but like any model, they simplify the situation and we try to derive consequences of our assumptions. It’s a mathematical model so we deduce what our assumptions indicate. We prove theorems, as they are called. But we also ask about the applicability of these theorems, these consequences in real life cases. So, one gets one’s inspiration usually from observing what happens in the real world, and those are the kinds of things I teach. But I try to make them more coherent, understand them at a more scientific level, by constructing a model. A model might be something like that if you can array the candidates on a left/right continuum, you will vote for the candidate closest to you. Now, that is complicated often by the fact that the person closest to you, the candidate, might be somebody who has little chance of winning. So you might want to alter your choice to vote for a more viable second choice, or third choice.

A good example of this was the 2000 U.S. Presidential election in which Ralph Nader was a third-party candidate. He ended up getting less than 3% of the popular vote; he won no states, so he got no electoral votes. And Nader supporters, generally on the far left, were torn. Should they vote for Nader, who had no chance of winning, or should they switch to a second choice? For many of the Nader supporters, that would have been a Democrat, Al Gore. And in some cases they were torn. And one consequence of being torn is you don’t vote at all. You can’t make up your mind. But some switched, and some did not switch. Of course the major consequence was that enough stuck with Nader so that he, by all accounts, affected the election outcome. In particular, in Florida, Bush in the end got about – he beat Gore by about 500 votes. But there were 97,000 Nader supporters in Florida, and if most of them had gone for Gore as a second choice, then Gore would have won by tens of thousands of votes instead of losing by about 500. That would have changed the outcome in the country as a whole and we would have had a different President. So that’s a good example of a so-called “spoiler,” somebody who can’t win, who changes the election outcome.

So those are the kinds of situations that we study, and I think these models are very helpful in understanding them.

Question: How can your models help voters make the most rational decision in a given election?

Steven Brams: Well I think, what I just suggested about the 2000 election is the example. If you feel that the consequences of electing Bush, let’s say you’re a Democrat, far left leaning, are sufficiently problematic and you are a Nader supporter, then you might well switch. That would be the rational choice. But if you think neither candidate was very good, as Nader argued, they were both cut of the same cloth, then you would not switch and your vote would be more of a protest vote.

So rationality will move voters in different directions depending on what their preference is, their goals. If you want to just protest, or do you want to affect an election outcome, or try to affect an election outcome?

Recorded on February 2, 2010
Interviewed by Austin Allen


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