Last year, Goldman Sachs handed out $16.4 billion in bonuses to all its employees. As Laurent Fischer points out, "That amount exceeds all corporate donations to charity in 2005. It is also nearly the entire worldwide amount spent annually to fight the global HIV/AIDS epidemic." But, of course, that money definitely should not go to HIV-prevention in Africa. It should go to those hardworking Goldman Sachs execs who dreamed up the bright idea of advising state governments to privatize their highways over the wishes of voters while, on the side, getting rich investing in toll roads...

Actually, never mind. The point of this post isn't to call for more class warfare. We'll save that for another day. Mostly I wanted to link to Emily Oster's piece in Esquire about AIDS in Africa, because it seemed to make some important points.

Here's the gist: To a certain degree, and without exaggerating things, HIV is relatively hard to transmit. Drug users sharing needles are at very high risk. Sex workers are at very high risk. Gay and bisexual men are at high risk. So are women having unprotected sex with high-risk men. But all else being equal, an HIV-free heterosexual man who has sex with a woman actually has a relatively low (though hardly nonzero) chance of contracting the virus. That is, with one major exception: If the sexual partners have other STDs—and the open sores that come with them—that makes transmission much, much more likely.

Well, Oster discovered that the difference between HIV infections rates in the United States and Africa can be largely explained by a greater prevalence of other STDs, especially herpes, in Africa. Because many STDs cause open sores, HIV transmission is four to five times more likely for each sexual encounter in Africa. If Oster's right, that means that one of the most effective HIV-prevention program might actually be to just treat those other STDs. The good news is that herpes, say, can be treated for as little as $3.50 a year, as opposed to the $300 a year it costs to treat AIDS. And it could save more lives. Although it's not clear that donors would get as enthused about opening their checkbook to pay for herpes treatment.

On the other hand, it's hard to figure out how big a role STDs play, and how important sexual behavior is. In another section, Oster suggests that Africa needs to "encourage safe sexual behavior" in order to reduce HIV infection rates down to U.S. levels. The problem is that "there have been very limited changes in sexual behavior on average." Granted, the United States bears some blame for promoting abstinence programs that don't work in Africa, but Oster says the biggest problem is simply poverty—people living in desolate areas with low life expectancies have little incentive to change their behavior. Not the happiest of conclusions.