This article studies mergers in markets where firms invest in a portfolio of research projects of different profitability and social value. The investment of a firm in one project imposes both a negative business-stealing and a positive business-giving externality on the rival firms. We show...

This paper studies how selling constraints, which refer to the inability of firms to attend to all the buyers who want to inspect their products, affect the equilibrium price and social welfare. We show that the price that maximizes social welfare is greater than the marginal cost. This is...