Estimating University Spillovers with Count Panel Data *

James J. Jozefowicz

This presentation estimates the patent-R&D relationship, an empirical counterpart to the knowledge production function, using count panel data. The data is an original panel of 353 firms investigating in R&D from 1984 to 1993 and applying for patents during that period. The number of patent applications submitted by firms is explained by current R&D spending levels in addition to intra-sector technological spillovers and university spillovers. A Poisson model with fixed effects, is estimated, taking into account both the discrete nature of the count dependent variable and firm specific unobserved heterogeneity. Analysis of the data reveals that university spillovers play a crucial role in the innovation process promoting patents with a magnitude comparable to that of current R&D and, as such, can be classified as diffusion spillovers.