I think if you look carefully through the source material, most of Engheim's data cannot easily be explained by economic disparity, even if that may play a role.

Rather than go through it one by one, though, I'll offer some of the clearest data of all, which comes from experiments where they send out resumes and look at the response rate. They send out identical resumes save for one thing: they use a name that is characteristically white or characteristically black. UC Berkeley and the University of Chicago did a huge study a few years back where they sent out eighty thousand applications that differed only by name. They found that the variations in name were associated with a 10% lower callback rate, and that some companies were substantially worse than others.

Most news reports covered this as, "Yep, still bad!', because this kind of study has been done before. But to me, this is quite encouraging, because twenty-odd years ago they did a similar but smaller study and the disparity was 50%--that's a big enough difference that it's almost certain to reflect an actual and major improvement in attitudes. (And there's another study that tested characteristically black African vs. U.S. black names and found that most of the effect went with U.S. black names, which suggests that it's more of an aversion to U.S. black culture than to skin color.)

It's also encouraging because 10% is very surmountable. Apply to 10% more jobs? Not such a big deal. Apply to twice as many? Doable, but rather more onerous.

But 10% is still discouraging because the effect is from such a slight piece of information--just a name--and that's enough to cause an effect, small though it might be.