This paper studies the impact of process and product innovations introduced by firms on employment growth in these firms. A simple model that relates employment growth to process innovations and to the growth of sales separately due to innovative and unchanged products is developed and estimated using comparable firm-level data from France, Germany, Spain and the UK. Results show that displacement effects induced by productivity growth in the production of old products are large, while those associated with process innovations, which are likely to be compensated by price decreases, appear to be small. The effects related to product innovations are, however, strong enough to overcompensate these displacement effects.

We develop a model of endogenous productivity change to examine the impact of the investment in knowledge on the productivity of firms. Our dynamic investment model extends the tradition of the knowledge capital model of Griliches (1979) that has remained a cornerstone of the productivity literature. Rather than constructing a stock of knowledge capital from a firm's observed R&D expenditures, we consider productivity to be unobservable to the econometrician. Our approach accounts for uncertainty, nonlinearity, and heterogeneity across firms in the link between R&D and productivity. We also derive a novel estimator for production functions in this setting.Using an unbalanced panel of more than 1800 Spanish manufacturing firms in nine industries during the 1990s, we provide evidence of nonlinearities as well as economically significant uncertainties in the R&D process. R&D expenditures play a key role in determining the differences in productivity across firms and the evolution of firm-level productivity over time. AbstractWe develop a model of endogenous productivity change to examine the impact of the investment in knowledge on the productivity of firms. Our dynamic investment model extends the tradition of the knowledge capital model of Griliches (1979) that has remained a cornerstone of the productivity literature. Rather than constructing a stock of knowledge capital from a firm's observed R&D expenditures, we consider productivity to be unobservable to the econometrician. Our approach accounts for uncertainty, nonlinearity, and heterogeneity across firms in the link between R&D and productivity. We also derive a novel estimator for production functions in this setting.Using an unbalanced panel of more than 1800 Spanish manufacturing firms in nine industries during the 1990s, we provide evidence of nonlinearities as well as economically significant uncertainties in the R&D process. R&D expenditures play a key role in determining the differences in productivity across firms and the evolution of firm-level productivity over time. * Earlier versions of this paper were circulated as "R&D and productivity: The knowledge capital model revisited" and "R&D and productivity: Estimating production functions when productivity is endogenous." We thank

This paper looks at the probability of introducing innovations by manufacturing firms at different stages of their lives. Once differences related to activity and size are controlled for, we examine how the probability of innovation varies over entry, post-entry ages, and advanced ages of mature firms. We also measure the association between exit from the market and pre-exit innovation. Results show that the probability of innovating widely varies by activity, and that small size per se broadly reduces the probability of innovation, but also that entrant firms tend to present the highest probability of innovation while the oldest firms tend to show lower innovative probabilities. Some sets of firms with intermediate ages also present a high probability of innovation, and exiting firms are clearly associated to lower levels of introducing process innovations.

This paper looks directly at the impact of firms' age and (process) innovations on productivity growth. A model that specifies productivity growth as an unknown function of these variables is devised and estimated using semiparametric methods. Results show that firms enter the market experiencing high productivity growth and that above-average growth rates tend to last for many years, but also that productivity growth of surviving firms converges. Process innovations at some point then lead to extra productivity growth, which also tends to persist somewhat attenuated for a number of years.JEL classification: D24; L6; O3