5(ish) Posts About Elections, Bias, and Numbers in Politics

It’s election day here in the US, so I thought I’d do a roundup of my favorite posts I’ve done in the past year about the political process and it’s various statistical pitfalls. Regular readers will recognize most of these, but I figured there were worth a repost before they stopped being relevant for another few years.  As always, these posts are meta/about the process type posts, and no candidates or positions are endorsed. The rest of you seem to have that covered quite nicely.

  1. How Do They Call Elections So Early? My most popular post so far this year, I walk through the statistical methods used to call elections before all the votes are counted. No idea if this will come in to play today, but if it does you’ll be TOTALLY prepared to explain this at your next cocktail party or whatever it is the kids do these days.
  2. 5 Studies About Politics and Bias to Get You Through Election Season In this post I do a roundup of my favorite studies on, well, politics and bias. Helpful if you want to figure out what your opponents are doing wrong, but even MORE helpful if you use it to re-examine some of your own beliefs.
  3. Two gendered voting studies. People love to study the secret forces driving individual genders to vote certain ways, but are those studies valid? I examined one study that attempted to link women’s voting patterns and menstrual cycles here, and one that attempted to link threats to men’s masculinity and their voting patterns here. Spoiler alert: I was underwhelmed by both.
  4. Two new logical fallacies (that I just made up) Not specific to politics, but aimed in that direction. I invented the Tim Tebow Fallacy for those situations when someone defends a majority opinion as though they were an oppressed minority. The Forrest Gump Fallacy I made up for those times when someone believes that their own personal life is actually reflective of a greater trend in America….when it doesn’t.
  5. My grandfather making fun of statistical illiteracy of political pundits 40 years ago. The original stats blogger in my family also got irritated by this stuff. Who would have thought.

As a final thought, if you’re in the US, go vote! No, it won’t make a statistically significant difference on the national, but I think there’s a benefit to being part of the process.

Probability Paper and Polling Corrections

This is another post from my grandfather’s newsletter (intro to that here). When I first mentioned his newsletter, I mentioned that he manufactured probability paper for people who needed to do advanced calculations in the days before computers. I found some cool examples while looking through the 1975 issues recently, so I thought I’d show them off here.  First was this paper, used to determine what the “true” polling percentage is when you have a lot of undecided voters. He was using an equation he called Seder’s method to adjust the pollsters predictions:


To use it, you find the percent of people who responded to the survey with a definite answer as the x-axis, then look to the right to find the percentage of people who made a particular choice. Once you have that data point, you draw a line to the left (the traditional y-axis to find out how many people will probably end up going with a particular choice once they have to make one.

I decided to try it based on a recent Quinnipiac presidential election poll (from June 29th, 2016). This has Clinton polling at 39%, Trump at 37%, Johnson at 8% and Stein at 4%, with 12% answering some combination of Unknown/Undecided/Maybe Won’t Vote/Maybe someone else. Here what this would look like filled out:


As you can see, it adjusts everyone a little upward, with a little more going toward those polling with the low numbers. Whether or not this is the correct adjustment is up for debate, but it’s a fun little tool to use for those who don’t like equations.

This particular one was actually one of his easy ones. Here’s the paper for getting confidence intervals for Bernoulli probabilities:


It looks complicated, but compared to doing it by hand, this was MUCH easier. To show how much time we have on our hands now that computers do the complicated stuff, check out my take on the Bernoulli distribution here. That’s what I do while SAS is importing my files. Ah, technology.