Tuesday, November 13, 2012

How to Lie With Statistics


Bill Kristol notes that “Four presidents in the last century have won more than 51 percent of the vote twice: Roosevelt, Eisenhower, Reagan and Obama”. I’m not sure why Kristol, a conservative, is promoting the idea that Obama has a mandate, but that’s up to him. I’m more interested in the remarkable bit of cherry-picking that led to this “only four presidents” statistic.

There was one way in which Obama’s victory was large: he won the electoral college 332-206. That’s a thrashing. But if you want to claim that Obama has a “popular mandate” — which people seem to interpret as an overwhelming preference of The People such that the opposition is morally obligated to give way — you can’t make that argument based on the electoral college, you have to look at the popular vote. That presents you with a challenge for the 2012 election, since Obama’s 2.7-point margin in the popular vote was the 12th-smallest out of the 57 elections we’ve had. There’s a nice sortable table at Wikipedia if you would like to look at the numbers.


This is actually a big problem in second wave representative systems (sadly not democracies); both sides play the game equally well now, come too close to eachother in popular vote or electoral college - then you win an election by a few hundred votes in Florida, what do you have the mandate for? For cutting taxes? For invading a country under false pretenses, causing deaths of thousands in the process?

Alternatively you dont win big in the popular vote, then you might get to sit on the desk, but dont have a mandate.  Oh and at the same time, the opposition also "won" the last election, they are now firmly entrenched in Congress, while crisis looms in the future.

Are these the signs of a functioning system?