A Poll Tax on Selfishness

On a wintry night a few weeks ago, I was walking with Aaron Edlin across the Harvard campus when he casually claimed that the “voter’s paradox” wasn’t generally true — that it could be rational for people to vote for purely instrumental reasons.

I did a double take, because the chance that my vote will change the result of any election in my lifetime is vanishingly small. People might vote because it gives them pleasure, or because of its expressive value, but most economists think that it would never be worth your while to vote in order to impact an election, because of the small probability that any one vote is “pivotal.” But Aaron, together with co-authors Andrew Gelman and Noah Kaplan, has written a very important article showing that it can be rational to vote if you care about other people. If you care even a little bit about the welfare of your fellow citizens, then as the electorate increases, even though the probability of being pivotal becomes small, the impact of being pivotal becomes large. Thus, it can be instrumentally rational to vote even in winner-take-all elections with very large number of voters.

This claim, at first, struck me as being true, but too cute. However, the article does have the following interesting implications:

1. As voter turnout drops, the probability of being a pivotal voter increases, while the benefits of being a pivotal voter remain constant (being a function of the number of people in society, and not the number of voters). This means that there will be a smaller turnout in regions in which socially minded voters find it worthwhile to vote.

2. The model also explains, from an instrumental perspective, a new reason why voters may care about electability. In the voter’s paradox world, it is hard to figure out not only why people vote, but why they vote for candidates who are not their first choice. Under the old view, since there was (almost) no chance that your vote would matter, if you voted, you might as well have expressed support for the candidate you liked best. But Edlin’s model suggests that the probability of being pivotal will be higher for one of the dominant two candidates than it will be for a third-party candidate. So Edlin voters might find it rational to vote for second-best candidates who have a higher chance of winning.

Still, to my mind, the neatest implication of the model is that it suggests that publicly minded citizens will have a much larger say in our polity. In Edlin’s model, selfish citizens will not vote, and publicly minded citizens will. Indeed, the more you care about your fellow citizens, the more likely you are to vote.

The unwillingness of the U.S. system to bribe people to vote, or (as Australia does) punish people who don’t vote, operates as a kind of a poll tax on the selfish citizens who care only about themselves. Is it a good idea to promote this kind of selfishness selection, or should we mandate (or affirmatively incentivize) voting? I’m not sure. But whether it is good or bad, the systematic censoring of selfish voters is something that has big implications for the kinds of policies we would expect government to adopt.

So if you live in Ohio or Texas (or Vermont or Rhode Island), and if you care about the welfare of your fellow Americans, make sure to vote.