If innovation is to be subsidized, a natural place to start is to increase the quantity and quality of human capital. Innovation, after all, begins with people. Simply stimulating the "demand side" through R&D subsidies and tax breaks may only drive up the price, rather than the volume of...

We simultaneously assess the contributions to productivity of three sources of research and development spillovers: geographic, technology and product-market proximity. To do this, we construct a new measure of geographic proximity that is based on the distribution of a firm's inventor locations...