Everyone Is Fundamentally Alike

Emily Oster describes the primary difference between economists and other social scientists (emphasis mine):

anthropologists, sociologists, and public-health officials . . . believe that cultural differences—differences in how entire groups of people think and act—account for broader social and regional trends. AIDS became a disaster in Africa, the thinking goes, because Africans didn't know how to deal with it.

Economists like me [Oster] don't trust that argument. We assume everyone is fundamentally alike; we believe circumstances, not culture, drive people's decisions, including decisions about sex and disease.

Oster then goes on to apply this methodological line of thinking to analyzing AIDS in Africa. Her conclusions?

1. It's the wrong disease to attack: Treating AIDS itself costs around $300 per year. There are reasons to provide AIDS treatment in Africa, but cost-effectiveness is not one of them.
2. It won't disappear until poverty does: To put it bluntly, if income and life expectancy in Africa were the same as they are in the United States, we would see the same change in sexual behavior—and the AIDS epidemic would begin to slow.
3. There is less of it than we thought, but it's spreading as fast as ever: My work suggests that the HIV rates reported by the UN are about three times too high. Which sounds like good news—but isn't. The overall number of HIV-positive people may be lower than we thought, but my study, which estimated changes in the infection rate over time, also drew a second, chilling conclusion: In Africa, HIV is spreading as quickly as ever.

While the assumption that we're all fundamentally alike may not be completely accurate, it is a powerful approximation that is quite useful. This assumption helps to crystalize thinking and leads to a whole host of accurate, insightful, and oftentimes counter-intuitive conclusions about human behavior.

Hattip Statistical Modelling