why academics are so liberal 

 I read in this morning's  New York Times  about research being conducted by two sociologists, Neil Gross (British Columbia) and Ethan Fosse (Harvard), on why academics tend to be left of center. That professors are more liberal than non-academics is a pretty well-known fact; at the same time, we don't have a good idea as to why this is. Previous research on this point has largely relied on anecdotal or qualitative techniques, so Gross and Fosse's paper, which relies on survey data, looks promising. A copy of the working paper is  here . 
 


 The paper uses data from the General Social Survey pooled over time (1974-2008, n = 325, once observations with missing outcomes were removed), where the dependent variable is a respondent's self-described ideological orientation on a seven-point scale.  

 The technique the authors use to test various hypotheses explaining the ideology gap is the Blinder-Oaxaca decomposition, which was developed by labor economists to estimate the role of individual predictors in observed divisions. For example, you could use the technique to try to gain traction on the factors that drive the wage gap between men and women. In this case, the authors used the technique to figure out the role of different variables -- religion, parents' education, tolerance, verbal skills, having lived in a foreign country, etc. -- in the ideological gap between professorial and non-professorial populations. (Note: In the interest of full disclosure, this technique is new to me.) 

 In terms of the ideology gap, it appears that having a graduate degree, being generally tolerant of people different than yourself, and lacking a strong religious affiliation are some of the factors most strongly explaining ideological differences between academics and non-academics. In fact, these variables explain roughly half of the observed gap. (Of course, this does not rule out that some confounder could explain all of these factors, as well as self-described ideology.) 

 Gross & Fosse go on to posit that a professorial career has developed over time a liberal reputation so that liberal people are more likely to be drawn to it. Their results do not seem to provide direct support for this, a fact they acknowledge; nonetheless, their research is interesting and is drawing some attention.  

 My take-away is that there still seems to be a lot of room for quantitative research on this navel-gazing question. If people have thoughts, I'd be keen to hear them.