What keeps conservatives out of academia?

John Tierney has another column (behind TimesSelect) about the lack of conservatives in academia. He paraphrases the justifications various professors have offered:

1. Conservatives do not value knowledge for its own sake.

2. Conservatives do not care about the social good.

3. Conservatives are too greedy to work for professors' wages.

4. Conservatives are too dumb to get tenure.

Tierney rejects all of that, and blames the disparity on "the structure of academia, where decisions about hiring are made by small independent groups of scholars":

They're subject to the law of group polarization, derived from studies of juries and other groups.

"If people are engaged in deliberation with like-minded others, they end up more confident, more homogenous and more extreme in their beliefs," said Cass Sunstein, a law professor at the University of Chicago. "If you have an English or history department that leans left, their interactions will push them further left."

Once liberals dominate a department, they can increase their majority by voting to award tenure to like-minded scholars. As liberals dominate a field, conservatives' work comes to be seen as fringe scholarship.

"The filtering out of conservatives in the job pipeline rarely works by outright blackballing," said Mark Bauerlein, a conservative who is an English professor at Emory. "It doesn't have to. The intellectual focus of the disciplines does that by itself."

Suppose, he said, you were a conservative who wanted to do a sociology dissertation on the debilitating effects of the European welfare state, or an English dissertation arguing that anticommunist literature from the mid-20th century was as valuable as the procommunist literature.

"You'd have a hard time finding a dissertation adviser, an interested publisher and a receptive hiring committee," Bauerlein said. "Your work just wouldn't look like relevant scholarship, and would be quietly set aside."

That sounds accurate to me.

Tierney concludes that the phenomenon ultimately hurts liberals in the political sphere because they can't draw on the ideas of liberals in academia, who have veered too far left to produce ideas that are appealing to American voters.