We analyze entry, pricing, and product design in a model with differentiated products. Market equilibrium can be "separating," with multiple sellers and a sorting of heterogeneous consumers across goods, or "exclusionary," with one seller serving all customer types. Entry into an initially...

<DIV>In 1998, health expenditures in the United States accounted for 12.9% of national income-the highest share of income devoted to health in the developed world. The United States also spends more on medical research than any other country-in 2000, the federal government dedicated $18.4 billion to...</div>

We define national security (NS) as public policies that protect the safety or welfare of a nation's citizens from substantial threats. NS capital provides societal insurance against widespread harm or catastrophe, so optimal NS investments may have very low expected rates of return. Investment...

<DIV>In 1998, health expenditures in the United States accounted for 12.9% of national income-the highest share of income devoted to health in the developed world. The United States also spends more on medical research than any other country-in 2000, the federal government dedicated $18.4 billion to...</div>