Bryan Caplan praises Charles Murray for highlighting the fact that many “investments” in education end in foreclosure — also known as “dropping out”:
[L]abor economists normally estimate the return to completed education. It only takes a small drop-out rate to drastically reduce the expected return of trying to complete a year of school. If the rate of return for a completed year of education is 10%, but 6% of students who start a year don’t finish (and waste a year of their lives plus tuition), the expected rate of return is only 3.4%! If the marginal student is less likely to finish than the average student, the effect is even more drastic.