Building on the current theory of industrial concentration, we analyze the relation between market size and product differentiation, and show how product differentiation impacts market share turbulence. Our basic results highlight that in markets where vertical product differentiation dominates,...

This chapter surveys the costs, risks, and challenges encountered in the progressive discovery and development of new pharmaceuticals. The changing methods by which drugs are discovered, the links between companies and academic science, the changing character of public regulation, and the sharp...