Counting how votes count

A rational person will vote, economists show, as an act of altruism.

Voting can look like a bum deal. After all, odds that your one vote will determine the outcome of the presidential election are extraordinarily low. Even if the election makes a very big difference to you personally — say, you’ll be $20,000 richer if your candidate gets elected — the chance that your vote will make the difference is so low that the expected payoff for voting is minuscule.