Case in Point
By Bryan Caplan
When it comes to the idea of “early intervention,” and the claims that it offers very high rates of return, does [James Heckman] have serious published critics?
Check out the largely excellent responses. My favorites:
From Eric Falkenstein:
Why isn’t Head Start relevant? For a couple decades, everyone thought it worked. Now, it appears to have no effect after first grade [link]
These claims of super normal returns are based on a few small-sample, quasi-randomized studies. Why focus on these small studies (the Perry Preschool program involved 123 kids, Abecedarian had 111) and ignore the big, more relevant stuff like Head Start?
Also, yes, Heckman has revised down his earlier claims of ginormous returns to a more modest 7% or so [link]
[R]ecent Heckman is a bit less enthused than earlier Heckman. For example, the main point of the Heckman (and students) re-do of the cost-benefit analysis from Perry Preschool is to bring the estimated effects into the domain of the realistic. They are still big by the standards of public programs but, unlike the ones sometimes advanced by the Perry people themselves, they do not elicit laughter as a first reaction. Also, my sense is that recent Heckman is pushing, as the evidence suggests, early interventions many for disadvantaged kids, not all kids. That is, after all, where the evidence is.