I strongly second Don Boudreaux’ recommendation to read this interview with James Heckman. A few excerpts (but do go read the whole thing):
what do the GEDs earn? They earn what high school dropouts who do not get GEDs earn, once you adjust for their somewhat higher cognitive ability…They’re missing motivation, self-control and forward-lookingness. I call these noncognitive skills.
…Most job training is actually being done in private companies, not in the public sector. And who is more likely to get private job training? People who have higher cognitive and noncognitive skills—the same abilities that helped them get the job in the first place. These people earn high returns to private job training.
…Richer families are much more likely to send their kids to college, but once one conditions on the ability of the child at age 17, virtually all of the income effect goes away. It’s all about the ability that’s embodied in the child from a lifetime of early investments.
…Cognitive skills such as IQ can’t really be changed much after ages 8 to 10. But with noncognitive skills there’s much more malleability.
…In some quarters of our profession, the level of discussion has sunk to the level of a New Yorker article: coffee-table articles about “cute” topics, papers using “clever” instruments. The authors of these papers are usually unclear about the economic questions they address, the data used to support their conclusions and the econometrics used to justify their estimates. This is a sad development that I hope is a passing fad.
From the latter passage, I’m guessing that Heckman is not a fan of a certain currently hot-selling economics book.