Actually, I was referring to home loans, and since banks have been required to gather this data since the Community Reinvestment Act of 1977, it is available, at least on mortgages.
And I am not surprised they default at a higher rate, because banks probably have to lend to them regardless of income, and also because a smaller percentage of blacks who begin college, finish it. (I presume that is the case from what I have read over the years, but have not researched it)
Income had little to do with it. Based on the passage I quoted, the defaulters' debt as a% of income was similar - it's just that black default rates per capita were way higher. Obviously not all blacks welsh on their debt. But the rate is way higher, even for a given level of income, just as for a given income level, an all-black town will have a per capita crime rate several times that of an all-white town.