What factors underlie industry differences in research intensity and productivity growth? We develop a multi … consumer preferences. We find that long run industry differences in both productivity growth and R&D intensity mainly reflect … research cannot account for industry differences in productivity growth rates, and that variation in intertemporal knowledge …

We build a model of firm entry and exit and show how returns to scale shape firm survival, the equilibrium productivity … and size distributions and firm concentration. High productivity dispersion and high concentration ratios need not reflect … productivity dispersion across establishments. Indeed, industries with lower returns to scale are characterized by higher …