This paper combines three prototype endogenous growth models, the models with human capital accumulation introduced by Uzawa [1965] and Lucas [1988], variety expansion by Romer [1990], and quality improvements by Aghion and Howitt [1992], in order to investigate how these three engines of growth...

By merging individual data on valuable patents granted in Prussia in the late nineteenth century with county level information on literacy and income tax revenues we show that increases in the stock of human capital not only improved workers ́productivity but also accelerated innovative...