Gross and Simmons' important new study of academic political ideology may underestimate the degree of liberal dominance because of the way it categorizes political "moderation" among academics. As discussed in my last post, the authors find that 43.5% of academics are liberal, 47% are "moderate," and 9% are conservative. This leads the authors to conclude that, while there are very few conservative academics, the overall valence of the academy is moderate rather than liberal.

One problem with this conclusion, discussed in my previous post, is that the preponderance of liberals is much greater in those fields where ideology actually matters. Another is Gross and Simmons' analysis of "moderation." As they explain, the "moderate" category in their Table 2 (reprinted in my earlier post) is actually a combination of survey respondents who described themselves as "slightly liberal" (18.1%), "middle of the road" (18.0%), or "slightly conservative" (10.5%). I wonder, however, whether these self-descriptions are based on a reference group of other academics (who are well to the left of the general population) or of the general public. Many people who do not follow survey research understandably define "moderation" relative to the orientations of the people they know. For academics, these reference groups are disproportionately likely to be other academics and nonacademics with ideological backgrounds similar to those of people in the academic world. The famous anecdote about the New York intellectual who couldn't believe that Nixon had won the 1972 election because no one he knew had voted Republican may be an exaggeration; but it does contain a kernel of truth. Thus, self-described "middle of the road" and "slightly liberal" academics - perhaps even "slightly conservative" ones - may be well to the left of center by the standards of the general population.

I cannot reliably prove or disprove this theory based on the data presented in the Gross and Simmons paper. But there are some indications that it captures an important part of what is going on. For example, Gross and Simmons found that 78% of their respondents voted for Kerry (77%) or Nader (1%) in the 2004 election, and only 21% for Bush (Bush won the popular vote by a narrow 51-48 margin in the general population). Assuming that most of the self-described conservatives (20 percent of the total sample, if you count the "slightly conservative") voted for Bush, this implies that nearly all of the self-described "slightly liberal" and "middle of the road" academics voted for Kerry. By contrast, CNN exit polls indicate that self-described "moderates" in the general population voted for Kerry by a much narrower 54-45 margin. While ideology is not the only influence on voting behavior, this result certainly suggests that self-described academic centrists are on average much further to the left than moderates in the general population.

UPDATE: I should note that while there is good reason to suspect that academic "moderates" overall are more liberal than those in the general population, it is impossible to tell from the Gross-Simmons paper how this breaks down in particular disciplines. For example, it is possible that self-described "middle of the road" academics in the hard sciences are more moderate than those in the social sciences and humanities.

UPDATE #2: It is worth pointing out that Gross and Simmons do not deny the fact that academics are more liberal than the general population. As they put it (pg. 72), "we would not contest the claim that professors are one of the most liberal occupational groups in American society, or that the professoriate is a Democratic stronghold." Their main original claims are that 1) academics are more moderate than usually assumed, and 2) there is more diversity of opinion among left of center academics than conservative critics claim. The first conclusion depends crucially on the authors' definition of moderation - the issue discussed in this post. The second may well be true. In fact, I suspect that it almost certainly is. There is likely considerable divergence between the roughly 20% of humanities and social science professors who describe themselves as "radical" (see my last post) and those who are mainstream liberals. However, this finding does not change the fact that academics are overwhelmingly on the left rather than the right. Political diversity among academics does exist, but much of it is confined within a truncated liberal to radical political spectrum.