Human Capital Growth in a Cross Section of U.S. Metropolitan Areas
This paper attempts to explore why some economies accumulate more human capital than others. Using a sample of more than 200 metropolitan areas in the U.S. over the years 1980, 1990, and 2000, the results reveal two consistently significant correlates of human capital growth.
Link
http://research.stlouisfed.org/wp/2005/2005-065.pdf