One Point for Nature Over Nuture

Most of the discussion about inequality deals with the impact of an individual's environment, which is of course very important. However, in a paper entitled What Happens When We Randomly Assign Children to Families? the author studies an adoption agency that places a random set of Korean children in American homes. Then after 30 years they compared the incomes of the adopted children and the biological children with parental income. Here are the conclusions:

Having a college educated mother increases an adoptee's probability of graduating from college by 7 percentage points, but raises a biological child's probability of graduating from college by 26 percentage points. In contrast, transmission of drinking and smoking behavior from parents to children is as strong for adoptees as for non-adoptees. For height, obesity, and income, transmission coefficients are significantly higher for non-adoptees than for adoptees.

Here's more from Tyler Cowen, who apparently has access to the whole paper.