As Posner's data indicate, the world AIDS problem is now largely concentrated in Sub-Saharan Africa. Even there, the incidence varies a lot, with approximately 10 percent of the sub-Saharan population infected with the HIV virus, and with some countries like South Africa having incidences of over 20 percent.
AIDS is a major problem for Africa not only because it has killed many millions of men, women, and children there, but also because it has further disorganized their economies, and pushed them further behind more rapidly growing parts of the world. A high incidence of AIDS produces a sluggish population and cuts work effort. A study by Jane Forston of Princeton University shows that young persons in areas with high HIV incidence invest less in their schooling than do those in comparable areas but with lower rates of HIV infections
Several studies have shown that sexual behavior in Africa did not change much after this virus was discovered, whereas it did change significantly in the United States after this discovery. The incidence of new cases of HIV infection began to decline in the United States as American populations at especially high risk, such as gay men, began to change their behavior: toward greater use of condoms, lower promiscuity--many bathhouses that catered to gays were forced to close by drop in business--and other changes. After the antiretroviral drugs were discovered, some of the behavior returned to what it had been.
Why didn't risky sexual behavior decline much in Africa, especially since antiretroviral drugs are much less common there? A study in progress by Emily Oster of the University of Chicago shows the importance of two "economic" factors. One is the lower income of Africans, which means that the gain to them in terms of lost future income from taking actions to reduce their exposure to the AIDS virus is smaller than it would be in a richer country like the United States. The second is that the much greater prospect in Africa of death at younger ages from other diseases, such as malaria, reduced the gain to them from lowering the risk of contracting the AIDS virus.
These factors are very important but perhaps not the whole story. Posner mentions several other candidates for the low response in Africa. Although undoubtedly some Africans are ignorant about what causes AIDS, this is probably no longer of crucial importance. For the rate of HIV infections is apparently not much lower among relatively well-educated Africans than among those with very little schooling, even after controlling for income and some other variables. Women are much more likely to become infected with the AIDS virus from heterosexual sex than are men, and women are less likely to infect others. The low status of women in many African countries may well explain their relatively high rates of AIDS infections there, but it does not help much in understanding the very high rates among men.
I share Posner's skepticism about the effectiveness of government aid from Western countries to fight AIDS in Africa. I am less convinced than he is that there is little value from the activities of private foundations and other private groups from the West that operate in Africa to try to reduce the incidence of the AIDS virus. These groups compete among themselves, and have been responsible I believe for some of the few bright spots in the African AIDS situation. They have had more flexibility than governments in setting up useful clinics that offer practical information and advise about this scourge. They have helped spread knowledge--such as the importance of circumcision in reducing vulnerability to AIDS--sometimes in opposition to the official policy of certain African nations.
I cannot claim, however, that I have seen any evidence evaluating the effectiveness of the large spending on AIDS in Africa by big foundations like the Gates foundation. I also do not know the answer to the more important question: how effective have these AIDS expenditures been relative to spending by these and other foundations on diseases elsewhere, or on anything else? Some might argue that the tax-exempt status that the U.S. grants its private foundations (see our discussion last week) should not apply to monies spent by foundations in Africa and other countries outside the United States. But that would imply that they should also not be allowed to support with tax-free dollars grants given to groups operating abroad, or to studies of urban activities in say India. These are types of activities supported by many American foundations. My own guess is that spending by American foundations to reduce the incidence of AIDS in Africa is at least as valuable to the interests of this country as much of what else these foundations spend their resources on.
Posner concludes that not much can be done to combat AIDS in Africa until African nations achieve better economic growth, more extensive education, improve the position of women, etc. These factors may be important, but Africa has made great strides in reducing deaths from other diseases during the decades since 1960. A reasonable expectation is that they will also do much better at combating deaths from AIDS, partly because the cost of the antiretroviral drugs will come down. I believe they will do better also because some African countries are beginning to adopt more sensible economic policies, and this has been reflected in good growth rates during the past few years.