Revised

Basic research is a public good, for which social returns may greatly exceed private ones. This paper develops an economic framework for evaluating the social benefits of medical research. We begin with a model of the economic value of health and life expectancy, which we apply to US data on overall and disease-specific mortality rates. We calculate (i) the social value of increased longevity that took place from 1970 to 1990 and, (ii) the social value of potential future progress against various major categories of disease. The historical gains from increased longevity have been enormous, on the order of $2.8 trillion annually from 1970 to 1990. The reduction in mortality from heart disease alone has increased the value of life by about $1.5 trillion per year over the 1970 to 1990 period. The potential gains from future innovations in health care are also extremely large. Eliminating deaths from heart disease would generate approximately $48 trillion in economic value while a cure for cancer would be worth $47 trillion. Even a modest 1 percent reduction in cancer mortality would be worth about $500 billion. Unless costs of treatment rise dramatically with the application of new medical knowledge, these estimates indicate that the social returns to investment in new medical knowledge are enormous. We acknowledge support from the Lasker Charitable Trust, the Milken Institute, and the Bradley Foundation. An earlier version was presented as the Thompson Lecture to th