If professors made $500k/year, would they be Republicans? (updated and corrected)

Only a tiny minority of American academics are Republicans, a fact that is a continuing source of angst for much of the political right, as well as quite a few centrists. It’s generally assumed that this fact requires some explanation specific to the way in which universities work. The implicit assumption is that the group of those qualified and willing to take up academic jobs is roughly representative of the US population, and therefore contains roughly equal numbers of Democrats and Republicans. To state that submission is to see immediately what’s wrong with it. As a group, academics are obviously not typical of the US population. They have much more education and significantly higher incomes, though not as high as those of highly educated Americans in general. We know that these two characteristics work in opposite directions politically. Other things equal, more income is positively associated with Republican voting while more education is associated with lower support. So, a proper test of the idea that there is something special about academic voting patterns would begin with a multiple regression incorporating income and education as explanatory variables, then see if a dummy variable for academic employment was (statistically and quantitatively) different from zero.

But this is a blog post, so I’m not going to bother with all that hard work. Rather, I’ll point to this New York times article about the voting patterns of doctors. It includes a bivariate regression of voting patterns on income, with specialisations marked as observations It includes a bivariate regression of voting patterns on income for a sample of 30 000 doctors. This graph shows the resulting regression and plots the mean values for different specializations





The midpoint, at which specialities are equally divided between Republicans and Democrats is about $325k. The graph stops at $200k, where the predicted proportion of Republicans is 30 per cent. Extrapolating way beyond the range of the data to $75k (the average salary for full-time faculty in US universities and colleges according to Wikipedia), the predicted proportion of Republicans would be around 10 per cent, which is what’s observed in the data.

That assumes that the education variable takes the same value for doctors as for professors, which isn’t quite right. The MD degree takes four years, while a PhD typically takes five. Moreover, much of the MD is taken up with the practical business of learning to do a specific (very important) job, and less with developing skills in argument and reasoning. To the extent that education might have effects on broader approaches to thinking about the world (including politics) I’d expect that grad school would have more of an impact (per year) than med school.

So, if anything, this analysis suggests that, at 10 per cent, Republicans are over-represented. On the other hand, it presents those on the right with a simple solution to the problem. Just raise academic salaries to $500,000 a year and you should see lots of Republican professors.