Postscripts

1.  On Sunday, the New York Times had a piece by Alec MacGillis called "Who Turned My Blue State Red?" on the question of why poor states vote Republican.  I started reading it with low expectations, but perked up when I read "the people who most rely on the safety-net programs secured by Democrats are, by and large, not voting against their own interests by electing Republicans. Rather, they are not voting, period."

Those of us who are interested in politics tend to forget that a lot of people, and probably a majority of working class people, don't vote even in Presidential elections.  In a post last year, I suggested that working-class turnout might have declined in states like West Virginia because of the decline of manufacturing and mining, so the people who continued to vote would be the local middle class.  Although they might have relatively low incomes by national standards, they would compare themselves to the local people who didn't have steady jobs.  From that perspective, they could be drawn to the Republicans, and especially sympathetic to the idea that poor people got that way because they made bad choices:  they could think of examples from personal experience.

MacGillis  seemed to be saying pretty much the same thing.  He basically took the traditional journalist's approach of going out and talking to people--he offered some survey evidence, but it seemed sort of tangential.  But it makes me think that someone should look at changes in the relationship between class and turnout by state.

2.  In my last post, I talked about the relationship between height, weight, and earnings for men and women. The obvious way to do it would have been to look at the relationship between body mass index (weight over height squared) and earnings.  I thought about doing it, but didn't want to to impose a constraint on the form of the relationship.   But then I realized that I had wound up imposing a constraint on the relationship anyway, so why not try it?  BMI turns out to be almost uncorrelated with height, so you can just look at the bivariate relationship between BMI and earnings.  I rounded BMI to the nearest whole number, took mean earnings, and smoothed the figures to reduce the influence of sampling error, producing:

There are some interesting and unexpected things here:
1.  There is a penalty for having a high BMI, but it's not much different for men and women.
2.  Contrary to what I thought based on the figures in the previous graph, women do not benefit from being thin. Predicted income is about the same in the whole "normal" range (actually a little higher in the upper reaches, although I don't think the difference is large enough to be worth taking seriously).
3.  Men suffer a substantial loss from being "underweight."  That does match the results from my previous post.

Putting it together, it looks like men are the ones who lose the most if they don't have the "ideal" body.  I don't really believe this--the numbers of men with low values of BMI are small, so I suspect that most or all of the apparent difference is just chance variation.  But it's worth considering.