This paper studies mergers in markets where firms invest in a portfolio of research projects of different profitability and social value. The portfolio nature of the investment problem brings about novel insights on the external effects of firms' investments. The investment of a firm in one...

Are differences in inventor productivity due to differences in inventors’ skills or differences in the capabilities of the firms they work for? We analyze a 37-year panel that tracks the patenting of U.S. inventors and find strong evidence for serial correlation in inventors’ productivity....