Adoption studies as Rorschach test

As mentioned before, some (including perhaps Sacerdote himself) look at Bruce Sacerdote's research and conclude that parents don't have that much influence on children. David Leonhardt looks at the same research and sees something entirely different:

On Mr. Mankiw’s specific point, though, not all economists have the same view of the research on parents that he does. Bruce Sacerdote at Dartmouth has done one of the most-cited studies, and it finds that parents can make an enormous difference. From the abstract:

I analyze a new set of data on Korean American adoptees who were quasi-randomly assigned to adoptive families. I find large effects on adoptees’ education, income and health from assignment to parents with more education and from assignment to smaller families. Parental education and family size are significantly more correlated with adoptee outcomes than are parental income or neighborhood characteristics. Outcomes such as drinking, smoking and the selectivity of college attended are more determined by nurture than is educational attainment.

I look at this and see a cautionary tale about the perils of drawing inferences from non-representative samples, but I'm a statistician and that's how we see most things.