This article in today's NY Times seems to be appropriate for this thread.
We see K-12 schools and colleges differently because we’re looking at two different yardsticks: the academic performance of the whole population of students in one case, the research performance of a small number of institutions in the other.
Instead, Piaac suggests that the wide disparities of knowledge and skill present among American schoolchildren are not ameliorated by higher education. If anything, they are magnified. In 2000, American 15-year-olds scored slightly above the international average. ... While American college graduates are far more knowledgeable than American nongraduates, creating a substantial “wage premium” for diploma holders, they look mediocre or worse compared to their college-educated peers in other nations.
