You’re probably familiar with the idea that voting is ‘irrational’. Your one vote doesn’t matter. Sure, there’s some tiny probability that after you vote, your preferred candidate will end up winning by one vote – and in that scenario your vote truly did matter. But outside of that Hollywood script, your vote probably won’t decide the outcome. So why bother with the whole rigmarole of voting? Worse still, imagine that your preferred candidate isn’t even one of the frontrunners. If you support the Greens or the Libertarians, then your tiny probability of deciding the election just got a whole lot tinier. What I’d like to do here is outline an alternative perspective: even in an electorate of millions, your vote still has a remarkably high probability of affecting the outcome.
You can see a great summary of ‘instrumental voting is irrational’ perspective from an interview with Phil Arena here, from Nate Silver’s work on the recent UK election, and even from Russell Brand’s related argument. Essentially their conclusion is that ‘instrumental voting’, that is, using your vote as an instrument to affect the election outcome, isn’t a good reason for voting because the probability that you will affect the outcome is so low. Instead, the only way voting can be considered rational is if you get some kind of psychological boost from voting – from fulfilling your civic duty – regardless of who wins.
But I’d argue that if we consider making two extra assumptions, instrumental voting starts to make more sense:
1) People are more likely to buy something if it costs 99c than if it costs $1.00.
2) Politicians pay very close attention to election results.
These aren’t controversial assumptions (are they?). Everything you buy, from candy to cars, is discounted by 1c so as to avoid the more frightening price that comes with adding another zero. And politicians’ livelihoods depend on elections, so it’s no great leap to assume that they are careful observers of election results.
These two assumptions imply that your vote might still be an effective instrument, even in a large electorate. Yes, it’s still true that your vote will not be the vote that makes the difference between winning and losing, but it has a much better chance of being the vote that makes the difference between 99 votes and 100 votes. If that small difference is significant to consumers, then I’d argue it’s also likely to be significant to politicians. That means that even if you still have no probability of affecting who wins the election, you now have a good probability of importantly affecting how they behave afterwards. The winning politician has to decide which interest groups to meet with, which bills to write or co-sponsor, and which issues to emphasize in their speeches. Politicians might not change a policy position just because the Greens won 100 rather than 99 votes, but if they notice how many votes the Greens won, then that might change their behaviour.
The difference between 99/100 is really just an extension of other arguments that voting is a ‘signal’, see here. But the extra point I want to add is that these signals are small but significant. If the 99/100 difference is significant, then every single vote has a good chance – perhaps 1/100 – of making a difference. It might seem like a stretch to say that the world will be more than trivially different if a vote total is at 100 rather than 99. But think about how closely politicians both inside and outside a given state watch these election results. Think about the other voters who might be paying attention, and the potential candidates and potential donors who might also be watching. If most firms in the marketplace believe that their profits will be higher if they price their goods at $xx.99 rather than $xxx, then is it so unreasonable to argue that outcomes will be genuinely different if vote totals for a niche party hit 100 rather than 99? Might Clinton behave differently if Sanders wins more than a certain number of votes? Might the recent fracking ban in New York be related to the strong performance of the Greens in the gubernatorial election? To make voting ‘instrumentally rational’, your vote doesn’t have to change the world, it only has to have an expected utility that outweighs the opportunity cost.
One of the things that struck me about Phil Arena’s interview was the he argued that charitable contributions were different from voting, because with charitable contributions, every little helps, whereas with voting, that’s not the case. I’ve taken the opposite position – not only does every vote matter for the signal that election results send to everyone who’s watching, but there’s a ‘bonus’ signal sent if you can cross the threshold from 99 to 100. And so rather than having a one-in-a-million chance of affecting the outcome, it’s down to one-in-a-hundred. Now, at the end of the day, I still think instrumental theories of voting leave a lot to be desired, but I think the economic metaphor here helps explain how even a small action can make a big difference.
Nice post, Ben. I agree there’s an important difference between voting for smaller parties and voting for larger parties, particularly in multiparty PR systems, as one’s probability of pushing the greens over an important threshold (say the one necessary to gain a single seat in the legislature) is significantly different than the probability of determining who will lead the next government. But I continue to think that the rarity with which vote results are reported (accurately) down to the single digits is a serious problem for instrumentalist arguments. In many cases, the media narrative is pretty well set before the counting is even done. By the time they sort out whether the Greens won 99 votes or 100, the post mortems may well have been conducted. That’s not always the case, but I think it’s far too optimistic to say that the odds of your vote making in difference in how people interpret the election results are 1 in 100.