Confronting AIDS.

By 2020, HIV/AIDS will be the leading infectious killer of young and middle-aged adults in the developing world. Past gains in life expectancy are already being eroded in some countries. Millions of lives can, however, be saved if developing country governments, the international community, and nongovernmental organizations act now. Although more than 11 million people have already died of AIDS, 2.3 billion people live in developing countries in which the disease has not yet spread beyond certain risk groups. If the spread of HIV is checked, the quality of care available to people who are infected with HIV will probably be better than it would be in the context of a full-blown AIDS epidemic. However, while governments need to respond urgently to HIV/AIDS, using resources to help people with AIDS will reduce the resources available for other investments, such as child education, providing safe drinking water, and building roads. Economics can help governments set priorities as they decide how best to allocate their available resources. Externalities, public goods, and redistribution are discussed. All countries will need to use some combination of preventive and coping measures.