Exhibit A right now is Marginal Revolution, where NYT columnist and GMU economist Tyler Cowen's desire to Hispanicize America in furtherance of Tyler's own exotic aesthetic tastes has led him to claim that he'll look for "useful" data on Mexican assimilation rates, then today ignore the enormous amount of useful data displayed in his own comments section, apparently on the grounds that it is not "useful" for furthering his policy desires.

Now, Tyler's co-blogger Alex Tabarrok is pushing "an open letter on immigration reflecting the consensus opinion of economists on the major issues," which is a compendium of sentimental clichés worthy of Oprah.

The bad news is that Tyler Cowen and Alex Tabarrok are are among the best of the bunch: smart guys, sensible and open-minded about most things, whom I read them every day. But, clearly, on immigration, as this impressive comment thread demonstrates, they've gone out of their way not to learn the facts and are allowing their emotions, tastes, and self-interests to drive their policy recommendations.

And Tyler and Alex are among the best of the bunch.

Steve Sailer: The Debacle of the Economists:

The funny thing is that I've quoted their stuff a couple of times, when they were talking about research that proved stereotypes: here, about research that shows that cab drivers are statistically correct when they claim that African-Americans don't tip well, and here, about massive corruption in the Mexican Judiciary.

But what I was totally not impressed by was this: in a Volokh Conspiracy post on the "Immigration reduces crime" myth, he wrote this:

Yes comments are open, but purely anecdotal accounts of how you were once mugged by a Mexican, or how your neighborhood just isn't "the same anymore" are discouraged.

That's the attitude of someone who just doesn't want to know.