Democracy and Coin Flips

By Patrick L. Warren

This is how the #IowaCaucus works. A tie is solved tossing a coin @HillaryClinton wins

— Fernando Peinado (@FernandoPeinado) February 2, 2016

We often argue that outcome-oriented voting is irrational because you are so unlikely to make a difference. Gelman, Silver and Edlin find, for instance, that the average American voter has about a 1 in 60 million chance of being decisive in the Presidential election. In some early related work, Barzel and Silberberg argue that voters are actually quite repsonsive to the probability of being pivotal. I was reminded of this work this morning when looking over the Iowa caucus results from last night, where the Democratic caucuses ended in no fewer than three ties, adjucated by coin-flips. Since the overall results were also quite close, we might have had multiple pivotal voters last night.