I enjoyed skimming a paper by Edlin, Kaplan, and Gelman on what motivates people to vote.

Snarky wags like to argue:  “It is a waste of your time to vote!  It is irrational.  So, it is stupid to bother.”    The  argument  goes as so: the cost/benefit doesn’t work.  So many things need to happen to capture any benefit.  Your vote would need to be critical.  He needs to win.  The benefit you hope for needs to get back to you.  If you get the benefit, how big can it be?  In some circles this is treated as conventional wisdom.

This argument is a tool of voter suppression, which is reason the meme is so virulent.  It an effective tool for convincing your opponents to say home on voting day.

The arguement gleans it’s gloss of credibly from the math like analysis and the appeal to that high principle: rationality.    You can dispute the arguement in assorted ways, for example substituting some other high principle such as responsibility or community.

The paper undermines the arguement on it’s own terms.  And it is very simple.

It is stupid to argue that the only rational benefit we get from voting is selfish.  Once you break the connection between rational and selfish the arithmetic changes.  Benefits have two components: one selfish and one unselfish.  Call that second one social benefit.  This changes everything because the social benefit is multiplied by the size of the population!  Put a million people into the population and even a 20 dollar benefit per citizen gets big.

Most of us think the per citizen benefit of our candidate winning is much larger than a few bucks.  Of course both the selfish-benefit term and the social-benefit term are discounted.  But notice that means the more social minded you are the more likely you are to vote.  One reason the “it is irrational to vote” line of arguement works to suppress is how it makes the selfish term more salient in the mind of the voter, making him forget his more socially aware side.

In fact most political activist usage of the rational choice ideas in political debate is playing that card.  I’ll note that this has changed clarified my thinking about mandatory voting laws.  I’ve always found them a bit distasteful.  I’ve had a few arguements for while I don’t like these laws. Coercing people into good behavior is a bit troubling – it seems to put the cart before the horse.  I’m also bothered by the tone of those who advocate such rules.  That tone has always seems scolding and righteous.  The model above provides another arguement; selfish is toxic to good governance.  Forcing selfish people to vote? I’m not sure that’s wise.

You can grab the paper here: Voting as a Rational Choice: Why and How People Vote to Improve the Well-Being of Others.  The paper is a bit more subtle, and hence interesting.