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...

Firms play a central role in the selection, sponsorship, and employment of skilled immigrants entering the United States for work through programs like the H-1B visa. This role has not been widely recognized in the literature, and the data to better understand it have only recently become...