PEW has a new study (pdf) out on the characteristics of interracial marriages in the U.S.
As you can see, not only is there a clear racial hierarchy in terms of education and earnings, but the interracial marriages have a similar hierarchy. Interesting findings: while asian-asian marriages have higher levels of both spouses having college education than white-asian marriages, white-asian marriages earn more; also, white male/black female marriages make slightly more than the white-white average, but white female/black male, make significantly less
Here is graph showing that those whites marrying asians are significantly better educated – whereas, among white women, there is a trend for those marrying blacks to be less educated:
Among blacks and hispanics, both men and women marrying whites tended to be better educated than those who married within their race, but by varying amounts (black women were 7% more likely to have a college degree, but black men only 2%; hispanic women were 20% more likely to have a college degree, and hispanic men, 12%). For asians, there was very little difference in education whether they married whites or asians.
Final note: given the prevalence of cohabitation, and declining marriage rates, this data is probably somewhat misleading. I already went over the differences in rates of interracial cohabitation vs marriage. If those relationships were counted, it would probably widen the gap found here. For example, asian-male/white-female marriages were more likely than black-male/white-female marriages, given their respective proportions of the population. However, that was strongly reversed in cohabitation rates. Since marriage vs. cohabitation is partly a class issue, this fits into the data here, and would probably make it stronger.