The expected utility of voting

In the comments thread to Chris’ post on tactical voting at Crooked Timber, Michael Otsuka very sensibly suggests

I believe there’s an extensive, sophisticated social science literature on the expected utility of voting in elections which has made some progress beyond the speculations posted above. Could anyone who’s up-to-speed post a reference to an accessible summary to save us the trouble of trying to reinvent the wheel?

This brings me to one of those papers I’ve been meaning to write for years (I wrote a several drafts of a joint paper with Geoff Brennan, but we never quite converged), and which has finally (2005!) been written by someone else. The idea was to prove an assertion I’ve made quite a few times in academic papers, and here at CT, that, as long as voters have ‘social’ rather than ‘egoistic’ preferences, the expected utility of voting is independent of the size of the electorate, and potentially large enough to justify high levels of participation. You can read this paper by Edlin, Gelman and Kaplan (PDF file). There’s an excellent appendix on why the probability of a decisive vote is of order 1/n.

There’s still the question of why people vote when one side or the other is bound to win. EGK have a go at this, and in my paper[1] on the subject, I say

This approach, in which b [the social benefit of the preferred party winning] is a simple step- function, may be replaced by a more sophisticated one in which b depends not only on the party elected, but on the size of its majority. This would be consistent with the fact that there is a substantial, though normally reduced, turnouts in elections which are perceived as foregone conclusions.)

That’s not a complete solution, and I think it’s also important to consider that voting per se is considered as a social duty or as yielding social benefits, but I think it’s at least as important as expressive motives.

fn1. Quiggin, J. (1987), Egoistic rationality and public choice: a critical review of theory and evidence’, Economic Record 63(180), 10–21.

3 thoughts on “The expected utility of voting

  1. I glanced at the Edlin et al paper. It’s jargon-riddled and very abstract. Why talk about “utility” without at least giving examples to illustrate the meaning? Well, I only looked at two pages before losing patience.

    “There’s still the question of why people vote when one side or the other is bound to win.”

    Why not ask them? Why vote Green though there isn’t the remotest chance for the Green candidate? Simple. Such a voter is not narrowly looking to an election outcome as though this was the whole point and purpose of politics. Rat choice not only imputes selfishness but sees elections as some kind of grand final. Our Green voter is looking to genuinely influence politics.

    Green preference dealing saves a park here, extracts a promise for funding for a study there – in short actually participates in government.

    Does the voter need to think “socially” to vote Green? No. He or she can have a vested interest in the park or the funding. On the other hand, in a safe seat I don’t quite see how it would be possible to vote “selfishly”.

  2. The question as to why a person votes when he/she believes one or the other side is certain to win only arises if you adopt a rational choice view of democracy. This view, due to Anthony Downs (1957), sees voters as rational consumers (rational, in the narrow sense of neo-classical economics) who choose between competing “products” at elections. The products are proposals for political action, or (equivalently), philosophies of action-proposal-construction. In other words, this rational choice model of democracy views citizens as passive consumers of political ideas, and not their producers. It therefore has difficulty in explaining lots of democratic phenomena, such as grass-roots political activity or public demonstrations, or voting when you know your party will lose.

    An alternative theory of democracy (due to Michelman, Habermas, and others) is a collection of ideas called “deliberative democracy”, in which citizens are seen as producers as well as consumers of political ideas and proposals for action. In these theories, a rational citizen (rational, in the broader and much older sense of argumentation theory) engages in political activity not only because they wish to influence the outcomes of political decisions, but also because they themselves are open to persuasion. One person’s chance of persuading another to his/her view falls dramatically if that second person believes the first is not also themselves willing to change their mind.

    The deliberative viewpoint, IMO, explains much more everyday political phenomena than does the rational choice model, including why people vote when then their favoured party will lose: eg, they do so to ensure their ideas are represented, and/or to send a message to the majority, and/or to indicate a willingness to engage in the process. All these are perfectly rational actions when the actor is a producer as well as a consumer of political ideas. Of course, they assume that the citizen has some notion of solidarity with the other citizens in the polity which goes beyond mere self-interest, a notion which economists often have trouble understanding or even recognizing.

    It is interesting to see (years after some of us have been arguing this) that even a Nobel-winning economist now understoods that the economic definition of rationality is too narrow — see Amartya Sen’s book: “Rationality and Freedom” (2002). I doubt, however, that the majority of economists will ever accept a deliberative theory of democracy, as it contains too much implicit sociology.

  3. Or maybe it’s because unlike other demcracies around the world we are foreced to vote with the threat of legal sanction. It never entered the heads of our Founding Fathers that the right not to vote is a personal preference as well, after all we may have better things to do with our time. It would also forces the parties into thinking how to attract a big mass who couldn’t care less to the polls rather than forcing them to to pen to paper

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