This paper finds robust evidence that age structure matters for subsequent growth in per capita income across the US states 1920-1990. The age groups 25-65 year are positively related to subsequent per capita income growth. Another conclusion is that the average years of schooling affects...

Abstract <p> This paper introduces age-based population heterogeneity in the Mankiw, Romer, and Weil (1992)model to improve measurement of aggregate labor and aggregate human capital. The estimation results are consistent with this model, and they indicate a hump-shaped and quantitatively important...</p>