Americans are dumb...
2008-05-16 · Original WordPress address
... until they spend 10 years on the job market (pdf). Improvement in literacy (in the broad sense of the term) is most pronounced between 25-35 year olds and 35-45 year olds. This is to say the jump (or lack there of) in literacy between the college-graduate-aged cohort (25-35 year olds) and the high-school-graduate-aged cohort (16-25 year olds) is much less than the improvement later on in people's careers ((I saw a seminar yesterday in which it was suggested this isn't a so-called cohort effect, i.e. the older folks didn't get better educations.)). Doesn't say much for the impact of college, does it.
Also, American adults actually catch up to adults in other countries in literacy scores. Here's the US ranking (out of 19 countries) in the three types of literacy test by age groups ((see page 16 in Sum/Kirsch/Taggart 2002, linked above)):
Given Americans go to college at much higher rates than those in other countries (at least this was true when these literacy tests where administered), this is even more evidence for the signaling theory of higher education or it at least takes the wind out of the sails of the idea that colleges are good at creating human capital.
The catch-up effect suggests Americans are learning things on the job they should have learned in high school. Because we end up high in the rankings, though, this is more than just catch up. It seems there's something about the American labor market that makes it especially good at producing human capital.