A new paper, "Sexually Transmitted Infections, Sexual Behavior and the HIV/AIDS Epidemic"
by Harvard economics graduate student Emily Oster, asks why prevalence
rates for HIV/AIDS are ten to fifteen times higher in Africa than in
the United States. Using a simple model that decomposes infection
levels into differences in sexual behavior and differences in
transmission rates, she attributes the entire difference in HIV
prevalence between the United States and Sub-Saharan Africa to
differences in transmission rates. The intuition, as she writes, is
that "Higher transmission rates produce more infections this period,
and each new infected person can infect people next period, so the
result of a higher transmission rate is multiplied many times over."
of the implications of her findings is that lowering transmission rates
by targeting STDs is more cost effective than trying to reduce HIV
prevalence using expensive antiretrovirals or education programs aimed
at changing behavior.
Read more here.