All Gregory Mankiw, former chairman of the White House Council of Economic Advisers, did was post on his blog the headline "Preschool Pays" and link to the Joel Waldfogel Slate entry mentioned just above. That touched off a flurry of comments, pro and con. Many of the comments wrestle with the economic analyses themselves, especially what can be concluded from the Perry Preschool study of the effects of high quality preschool designed to serve the most disadvantaged. But some reflect the fears referenced by Waldfogel, that good quality voluntary preschool undermines the family and replaces parents with "government agents." (One has to think that if preschool teachers really were government agents they'd be earning a lot more money!).

In any case, I urge economists or journalists who are examining the economic returns of investing in preschool to start with the superb "Dollars and Sense" report to gain perspective. Although put out by a group that advocates for universal preschool, the report examines the strengths and weaknesses and generalizability of various analyses of economic returns from preschool. It also acknowledges the bias of Pre-K Now, which issued the report.