R&D heterogeneity and implications for growth

This paper quantifies the determinants of R&D investment heterogeneity and its implications for growth. We estimate a Schumpeterian growth model with heterogeneous firms, à la Lentz and Mortensen (2008), in which firms differ with respect to innovation efficiency. Using observations on size, productivity, and R&D expenditures from a panel of Norwegian manufacturing firms we find that the model has a good fit to the data. In particular, it fits the distribution of R&D investment (mean, dispersion and skewness) as well as the negative correlation between research intensity and size. Moreover, the model generates firm-level investment responses to R&D subsidies that are in line with micro evidence from a natural experiment. The model estimates imply that a large part of aggregate productivity growth (72 percent) is the result of the market directing R&D resources to the more innovative firms. Finally, we study the link between firm heterogeneity and R&D subsidies, and show that the growth effects of subsidies depend crucially on how the policy influences the equilibrium distribution of firms. We address these questions by estimating an equilibrium model of firm-level innovation and growth. We adopt the micro-macro framework growth in Klette and Kortum (2004). Using observations on size, productivity and R&D expenditures from a panel of Norwegian manufacturing firms, we estimate an extended version of the Klette-Kortum model, developed in Lentz and Mortensen (2008). The model estimates imply that a large part of aggregate productivity growth (72 percent) is the result of the market directing R&D resources to the more innovative firms. Using the estimated model we also show that the growth effects of R&D subsidies depend crucially on how the policy influences the equilibrium distribution of firms.