# The mathematics of democracy

With only a few days left until the U.S. presidential elections, I thought it would be appropriate to write about some of the mathematical and teaching opportunities an event like this provides. Especially because this has such a high profile in the general public, talking about election-related mathematics is much easier than just talking about math on any other day. Here are a few of the things that I have been talking about with my family during dinner, sharing with friends on facebook, and if I were teaching classes this semester I would like my students to read and discuss.

1. Nate Silver and 538: One of my favorite things to read these days (and for the last month or so) is Nate Silver‘s blog, 538, on the New York Times site. Silver is a statistician who became famous for his predictive analysis of the performance of baseball players, and later on for his predictions on the 2008 elections based on polling data. I think this blog is filled with fabulous reading for a stats class. In particular, Silver is very careful to keep a very mathematical and level-headed point of view. He describes where he obtains all his data, where potential noise or inaccuracies may be coming from, and updates his predictions as more polling data gets published. In fact, he writes a post almost every day. I hope someone is having their students read this. A new, surprising development (at least, surprising to me), is all the backlash that Silver has been getting from some pundits in the media. Part of what Silver does is predict who will be the winner of the election, and given the polling data from each state and the general trends, he computes a probability of winning for each candidate. Conservatives seemed to be very angry that Obama gets (from Silver) a 77.4% chance of winning the election, and claim that his analysis is biased and inaccurate. The main problem seems to be that many people don’t seem to grasp that a probability, no matter how high, is not a certainty. Also, Romney is hardly playing the lottery here, many people would bet on those odds. A few friends of mine shared some good replies to the backlash, and in defense of Silver’s methods, like the Salon post, Jordan Ellenberg‘s blog post, and this response on the Washington Post. I think having the students read the criticism of Nate Silver’s predictions on Politico and then some of these responses would make for an excellent class discussion. Boy I wish I were teaching stats this semester. That is really the fun of it: seeing probability and statistics being used in a real-life situation and understanding when they are being used correctly or incorrectly.