Recent work highlights a falling entry rate of new firms and a rising market share of large firms in the United States. To understand how these changing firm demographics have affected growth, we decompose productivity growth into the firms doing the innovating. We trace how much each firm...

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...

What form of intellectual property rights (IPR) policy contributes to economic growth? Should technological followers be able to license the products of technological leaders? Should a company with a large technological lead receive the same IPR protection as a company with a more limited lead?...