I have been listening to a talk by Emily Oster, an economist, on HIV infections in
Africa. She contrasts the dramatic sexual behaviour change of US homosexual men in the 1980s with the minimal behaviour change in heterosexual people in Africa. She does not attribute the difference to culture, education or knowledge but postulates that the main driver is the economic one of cost versus benefit.
Life expectancy in many parts of sub-Sahara Africa is low – 40 years compared with 80 years in the
. Forgoing sex, being faithful or wearing a condom is a cost which has to be weighed against the expected benefit of not dying in the next 10 years of AIDS. If their expectancy is only around another 10 years in any event, the personal benefit to them would not be great and the incentive for behaviour change low. In contrast the benefit of not dying in the next ten years is high in the case of someone expecting to live for another forty or fifty years and the motivation for behaviour change correspondingly high. US
A major cause of non-HIV related early mortality in
Africa is malaria. Life expectancy in areas where there is a low incidence of malaria is higher than in those where the incidence is high. Dr Oster’s model predicts that there would be more behaviour change, and lower HIV infection rates, in areas where there was less malaria and the data she presents appears to confirm this.
Let’s look beyond behaviour which would increase the likelihood of acquiring HIV to behaviour increasing the likelihood of dying from anything. Although Dr Oster specifically discounts cultural influences as behavioural determinants I would suggest that perhaps religious belief may be a non-trivial cultural influence on people’s perception of the benefit to them of increased longevity.
For over forty years, since I first visited a ‘third world’ country, I have been puzzled why people outside the ‘first world’ regard their own lives as so cheap. The most incredible and unnecessary risks are taken which are nothing to do with lack of material resources – in fact often material resources are wasted trying to copy western extravagance. Simple planning rather than expensive health care for a few could do so much to reduce loss of life and sickness. Planners and engineers using appropriate local technology could do far more than expensively trained doctors.
About fifteen years ago I heard about the theories of Thomas Robert Malthus (1766-1834). Malthus held that the greatest danger was over-population and the best means of combating it would be to allow the poor to die young. Rather than employing public health interventions and treating disease the poor should be crowded together near stagnant pools and other unwholesome situations. Cleanliness should be positively discouraged and attempts to eliminate ravaging diseases should be stopped.