We develop a microeconomic model of endogenous growth where clean and dirty technologies compete in production and innovation. in the sense that research can be directed to either clean or dirty technologies. If dirty technologies are more advanced to start with, the potential transition to...

We build a model of firm-level innovation, productivity growth and reallocation featuring endogenous entry and exit. A new and central economic force is the selection between high- and low-type firms, which differ in terms of their innovative capacity. We estimate the parameters of the model...

I present a model of financing social enterprises to delineate the role of impact investors relative to “pure” philanthropists. I characterize the optimal scale and structure of a social enterprise when financed by grants, and when financed by investments. The analysis yields two heuristics...

How is economic policy made? In this paper we study a key determinant of the answer to the question: lobbying by firms. Estimating a binary choice model of firm behavior, we find significant evidence for the idea that barriers to entry induce persistence in lobbying. The existence of these costs...