The ideas production function is at the heart of endogenous growth theory. Using data for Europe, its offshoots, and the Asian Tiger economies over the period from 1870 to 2010, this paper provides direct estimates of an ideas production function that explicitly distinguishes between the first- and second-generation endogenous growth models while allowing for human capital and international knowledge spillovers through various channels. The estimates show strong intertemporal and cross-country knowledge spillovers, provide robust support for Schumpeterian growth theory, and suggest that human capital and some channels of international knowledge spillover are influential for ideas production.