Monday, May 17, 2010

Emily Oster flips our thinking on AIDS in Africa

By Kaitlynn S.

The TED talk that I chose to analyse was “Emily Oster flips our thinking on AIDS in Africa” According to TED, “Emily Oster, who is a University of Chicago economist, re-examines the stats on AIDS in Africa from an economic perspective and reaches a stunning conclusion: Everything we know about the spread of HIV on the continent is wrong.” (Emily Oster flips our thinking on AIDS in Africa | Video on

In this TED talk by Emily Oster, she explains to her audience that what you may or may not know about the spread of AIDS in Africa is wrong. “So I want to talk to you today about AIDS in sub-Saharan Africa. And this is a pretty well-educated audience, so I imagine you all know something about AIDS. You probably know that roughly 25 million people in Africa are infected with the virus, and that AIDS is a disease of poverty. And that if we can bring Africa out of poverty, we would decrease AIDS as well. If you know something more, you probably know that Uganda, to date, is the only country in sub-Saharan Africa that has had success in combating the epidemic, using a campaign that encouraged people to abstain, be faithful, and use condoms -- the ABC campaign. They decreased their prevalence in the 1990s from about 15 percent to 6 percent over just a few years. If you follow policy, you probably know that a few years ago the president pledged 15 billion dollars to fight the epidemic over five years, and a lot of that money is going to go to programs that try to replicate Uganda and use behaviour change to encourage people and decrease the epidemic” [Emily Oster] Emily Oster then continues to explain to the audience about how she is going to talk about some things they might not know about epidemic, and challenge some of the things they do know about it, and to do this she would use her research as an economist on the epidemic. She tells the audience that everyone thinks AIDS is a policy issue; she then explains that this talk will be about understanding the facts about the epidemic; thinking about how it evolves, and how people respond to it.The first thing that I want to talk about, the first thing I think we need to understand, is: How do people respond to the epidemic? So AIDS is a sexually transmitted infection, and it kills you. So this means that in a place with a lot of AIDS, there's a really significant cost of sex. If you're an uninfected man living in Botswana, where the HIV rate is 30 percent, if you have one more partner this year -- a long-term partner, girlfriend, mistress -- your chance of dying in 10 years increases by three percentage points.” [Emily Oster] Emily Oster then explains that what people are trying to say to the people in Africa is that they should have less sex to decrease the spread of HIV. She states a fact that “ among gay men in the US we did see that kind of change in the 1980s. So if we look in this particularly high-risk sample, and they're being asked, "Did you have more than one unprotected sexual partner in the last two months?" Over a period from '84 to '88, that share drops from about 85 percent to 55 percent. It's a huge change, in a very short period of time.”[Emily Oster] In Africa, economist did not see that kind of change. Emily explains that the epidemic is getting worse. People are starting to learn more about this issue, but there is no change in sexual behaviours (two percentage points.) To try to help the audience understand more Emily explains about health the way economists or herself look at it -- as an investment.So if you're a software engineer and you're trying to think about whether to add some new functionality to your program, it's important to think about how much it costs. It's also important to think about what the benefit is. And one part of that benefit is how much longer you think this program is going to be active. If version 10 is coming out next week, there's no point in adding more functionality into version nine.” [Emily Oster] She continues to say that this assumption is the same about your health. She uses an example about every time you go to the gym instead of to the movies, or eating a carrot instead of a cookie, is a costly investment to your health. “But how much you want to invest is going to depend on how much longer you expect to live in the future -- even if you don't make those investments. AIDS is the same kind of thing. It's costly to avoid AIDS. People really like to have sex. But you know, it has a benefit in terms of future longevity. But life expectancy in Africa, even without AIDS, is really, really low: 40 or 50 years in a lot of places. I think it's possible, if we think about that intuition, and think about that fact, that maybe that explains some of this low behaviour change.” [Emily Oster] Emily Oster then looks at the area with high, medium and low malaria. She finds that the areas with low levels of malaria, the number of sexual partners is decreased and a lot of HIV prevalence goes up, areas with medium levels of malaria do not decrease in sexual partners as much as the lower levels, and areas with high levels of malaria increase a little in sexual partners, although that's not significant. It also tells us something about policy. Even if you only cared about AIDS in Africa, it might still be a good idea to invest in malaria, in combating poor indoor air quality, improving maternal mortality rates, because if you improve those things, then people are going to have an incentive to avoid AIDS on their own. But it also tells us something about one of these facts that we talked about before. Education campaigns, like the one that the president is focusing on in his funding, may not be enough. At least not alone. If people have no incentive to avoid AIDS on their own -- even if they know everything about the disease -- they still may not change their behaviour.” [Emily Oster] Emily Oster then continues to talk about how AIDS is not going to fix itself so we need to start thinking about what policies would be effective, like the ABC campaign. In Uganda we see the prevalence went down, telling us that it worked. She then goes on about how there was no good research/data of HIV and AIDs in Africa until 2003. This is a problem for policy. “ It was a problem for my research. And I started thinking about how else might we figure out what the prevalence of HIV was in Africa in the past. And I think that the answer is, we can look at mortality data, and we can use mortality data to figure out what the prevalence was in the past. To do this, we're going to have to rely on the fact that AIDS is a very specific kind of disease. It kills people in the prime of their lives. Not a lot of other diseases have that profile. And you can see here: this is a graph of death rates by age in Botswana and Egypt. Botswana is a place with a lot of AIDS; Egypt is a place without a lot of AIDS. And you see they have pretty similar death rates among young kids and old people. That suggests it's pretty similar levels of development. But in this middle region, between 20 and 45, the death rates in Botswana are much, much, much higher than in Egypt. But since there are very few other diseases that kill people, we can really attribute that mortality to HIV. But because people who died this year of AIDS got it a few years ago, we can use this data on mortality to figure out what HIV prevalence was in the past. So it turns out, if you use this technique, actually your estimates of prevalence are very close to what we get from testing random samples in the population -- but they're very, very different than what UNAIDS tells us the prevalences are.” [Emily Oster] Emily Oster then goes back to the beginning of her talk about a face that 25 million people being affected by AIDS, if you think that the UNAIDS numbers are much too high, maybe that's more like 10 or 15 million. So then she tells the audience that she wants to use the new data to try to figure out what makes the HIV epidemic grow faster or slower. She then continues to go on that she mentioned that Uganda was the only country in Sub-Africa that is successful with prevention. Countries like Kenya, Tanzania, and South Africa have caught on. She questions that statement. It is true that Uganda had a decrease in prevalence in the 1990a, and they had a education campaign but there was also something else going on as well. “There was a big decline in coffee prices. Coffee is Uganda's major export. Their exports went down a lot in the early 1990s -- and actually that decline lines up really, really closely with this decline in new HIV infections.” [Emily Oster] Emily Oster then continues by comparing graphs (graphs about malaria and export ) that she showed the audience. “So if you combine the intuition and this figure with some of the data that I talked about before, it suggests that somewhere between 25 percent and 50 percent of the decline in prevalence in Uganda actually would have happened even without any education campaign.” [Emily Oster] she then goes on to say that we are spending a lot of money on this campaign when it is only 50% affective then what people really think it is. “Trying to change transmission rates by treating other sexually transmitted diseases. Trying to change them by engaging in male circumcision. There's tons of other things that we should think about doing. And maybe this tells us that we should be thinking more about those things.” [Emily Oster] In conclusion, she hopes that she has told the audience something that they didn’t know about AIDs in Africa, and made people question and rethink about the facts they already knew. “And I hope that I've convinced you maybe that it's important to understand things about the epidemic, in order to think about policy.” [Emily Oster]

I think this talk is a big eye opener to many people about AIDS. Before I heard this talk, I had idea about the AIDS in Africa. I knew a lot of people had it but it was a total shock that fifteen million people are affected by this terrible disease. At the beginning of her presentation Emily gave you some pretty devastating facts about AIDs in Sub-Africa and it was interesting that as she went on throughout her talk she kept coming back to these facts and adjusting them. It made me more intrigued to listen about what she was saying, also it made me and the rest her audience look at how AIDS is so easily spread in Africa. Not only did this talk make me look at AIDS from a different view, like how malaria, exports, etc may be a factor, but it made me want to do something about this terrible issue that is occurring in our world. It makes me realize how lucky I am to live in a place I do. It also makes me feel guilty, and now I am inspired to do something about AIDS in Africa.

In conclusion, we all need to work together and understand the epidemic. If everyone understood and examined the new facts about AIDS in Africa, people would be inspired to help out in making Africa a better place to life, AIDS free.

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