Economist Brad DeLong selectively deleted comments from a recent post that were contrary to his thesis. The comments were not ad hominem or inflamatory, but fact-filled and constructive. They were contrary to DeLong's argument, however, so he hoped they would go down the memory hole.

The idea had to do with the recent piece by Bruce T. Lahn of the University of Chicago, who found a gene associated with brain size was found with very different frequencies in different populations, suggesting it was selected for, and thus evidence of some sort of evolutionary selection. As a modern American liberal, DeLong pooh-poohed this observation, noting that under certain situations selection for dominant genes would not matter very long. In the debate that followed, certain researchers made the point that although most genetic variation is within-race, that does not mean races are "not real". This is because even though there is large within-race variation (85%), the correlation of genes within a race are sufficiently different that a geneticist would have no problem differentiating a Swede from a Hutu, just as no regular person would have difficulty differentiating a Swede from a Hutu. The deleted comments were technical extensions of this argument. DeLong obviously considered this blasphemous, or at least inconvenient.

Such tactics (deleting factual arguments) represents a frustration in an inability to counter an argument. Among people who make their living mainly through words and arguments, it's hard to imagine a more pathetic tactic. I'm sure DeLong prides himself on not "burning books" and supports such classics as Lady Chatterly's Lover, so how does he justify removing calm arguments about technical issues on genetics? I imagine his moral conviction blinds him to such considerations, as he sees his goal of promoting equality justifying these types transgressions, sort of like suspending civil rights during a war (which I'm for, btw). The problem for him is the Hapmap is coming, and he better learn to deal with it because it is much easier to argue when the facts are on your side.

It seems probable he applies this methodology to other issues he also deems important, such as progressive taxation or government spending, and thus makes him more like a political spinner than truth-seeking academic.