This paper demonstrates that a pollution tax with a fixed cost component capturing an “ambient tax” may lead, by itself, to stratification between clean and dirty firms without heterogeneous preferences or increasing returns. We construct a simple model with two locations and two industries...

We study pricing and product diffusion in a dynamic general equilibrium framework with product market frictions. Ongoing R&D activity leads, with an endogenously determined probability, to continual improvements in product quality. We characterize the steady-state equilibrium with endogenous...