raveneye

Actually the negative social consequences of preferential hiring and promotion have been known for a long time; in fact they were brought up in the recent Supreme Court case that found that most of such preferences are unconstitutional.

The Lott study (cited in the linked article) is not the only peer-reviewed publication that found these problems. There are others that are just as careful and thorough, eg citing similar problems with race preferences in law school admissions.

These are very well known by proponents of PT (preferential treatment). They are generally considered irrelevant, because the value of "diversity" is seen to trump these problems in all cases.

Consider college admissions: it would be easy to make admissions voluntarily blind, so that there is no discrimination. But this is not done in most places because the proportion of blacks, hispanics, and men in general would drop among the student population. Because this drop in "diversity" is seen as completely unacceptable, the quotas remain in place. So PT is really not about correcting discrimination. It's about maintaining diversity, regardless of the resulting problems created by this particular mechanism of maintaining diversity, problems that everybody is aware of.

Lott's study just confirms in detail what everybody knew already (I have the entire Lott study and several others as PDFs; if anybody is interested I can post excerpts).