Dan Klein has a newspaper column summarizing his research findings on the intellectual orthodoxy at Berkeley and Stanford in the Palo Alto Weekly newspaper.

From the article:

The popular vote for President went 48 percent Democrat and 51 percent Republican. This nearly one-to-one national diversity is unlike colleges and universities, where a one-party system prevails.

We have conducted a scholarly study of voter registration and find that among Berkeley faculty the Republicans are outnumbered 10 to 1. At Stanford the ratio is 7.6 to 1. Lumping both together gives 9 to 1. Talk about a lack of diversity! If this were a gender, race or ethnic-background study it would be considered almost evidence of discrimination.

Most striking, is that the faculties are becoming less intellectually diverse over time. At Berkeley, tenure-track hires at the Assistant Professor level are 30 to 1 Democratic to Republican and at Stanford it is 12 to 1. For Associate Professors, at Berkeley it is 64 to 1 and at Stanford the ratio is infinite--Stanford does not have a single Republican among its Associate Professors (and 40 Democrats).

Dan says that if this was a gender, race or ethnic-background study, it would considered "almost" evidence of discrimination. I think this understates the case--if the ratio of men to women hires at Berkeley was 30 to 1, that would almost certainly constitute a prima facie case of discrimination. Or to put it more practically, if this was the ratio of male to female hires at Berkeley, I don't think a hypothetical plaintiff would have too much trouble finding a lawyer who would take the case on contingency.

And to think that one reason that Larry Summers is in hot water because only 4 of the last 32 tenure-track hires at Harvard were women. I'm sure Stanford's students and faculty would be overwhelmed with joy at an 8 to 1 ratio of Democratic to Republican hires.

You can find the longer version of Dan's research on his homepage here.

Update:

Some clarifications in response to reader emails: First, the observation that the intellectual orthodoxy is getting worse is implicit in the numbers I originally quoted, but not obvious. At the Full Professor ranks, the ratio is 8 to 1 and 6 to 1 Democratic to Republican at Berkeley and Stanford respectively. The observation, thus, is that as full professors retire, and are replaced by the Associate and Assistant Professors, this ratio will worsen over time.

Second, it is true that Republican and Democrat imperfect proxies for intellectual diversity. For instance, many libertarians don't vote, and if they do, they don't register for any party--although I doubt there are so many uncounted libertarian professors at Berkeley and Stanford that it skews the numbers. But that's why it is important to read this article in connection with Klein's other paper, where he does a more nuanced analysis of public policy views, and discovers that views on particular public policy issues match up very closely with this study on Democratic vs. Republican professors. In that paper, he also captures a greater cross-section of instiutitions, beyond just Stanford and Berkeley. So the measure here just gives an easily-quantifiable measure that seems consistent with a more qualitative nuanced analysis.

Update:

Of course I'm a lawyer, so I can't do math, but if 4 of the 32 Harvard hires were women, that would mean there were 28 men and 4 women, which of course, would be 7 to 1 (not 8 to 1). So that's still better than ratio for the entire Stanford and Berkeley faculties and substantially better than for their recent hires.

Update:

There seems to be some ambiguity about what I wrote. First, I did not say that there was a bias here. I said that if we saw a ratio of 30 to 1 in a general population that we know to be roughly 1 to 1, this usually will create a prima facie case of bias. Then the the burden shifts to the other side to provide a nondiscriminatory explantion for what is observed. So that, for instance, it may be that there are no Republicans in the applicant pool--but that answer, of course, just shifts the analysis back one step, and has been quite plainly rejected in the context of women and minorities.

Second, and more fundamentally, this is key point--when Harvard hires 7 men to 1 woman, this is met with a blue ribbon panel tasked with the duty of getting to the bottom of things and finding out what is really going on. When Klein find a ratio of 30 to 1 Democrat to Republican, the academy has two responses. First, it simply denies the problem. Second, even if it is acknowleedged, the "response" is faculty lounge speculation and hand-waving about how this might all be rationalized. The irony, of course, is obvious--there aren't actually any conservatives there to participate in the conversation! Where is the blue-ribbon panel at Stanford on intellectual diversity? There may very well be a nondiscriminatory explanation here--but we'll never know unless we actually consider it to be a problem worth investigating and actually do the investigation.

Whatever the correct approach, surely it can't be that in one case we task a blue-ribbon panel of leading faculty members to find out what is going on and to recommend improvements, and in the other we shrug our shoulders and sit around and simply speculate?