Marginal Revolution: Nature, Nurture and Income
The income of adult children tends to reflect their parents income. Is this due to nurture (better schooling, more advantages, social connections) or nature (shared genes).
Bruce Sacerdote provides an answer based on adoption studies. The answer appears to be the genes.
I'd have been surprised by any other result; this tracks with other studies on the inheritance of IQ. What's interesting, however, is that even in the range of more common (?average) parental incomes the adoptee income seems quite low.