Bryan Caplan  

AIDS in Africa: Too Bad to Be True

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I've long been skeptical of the statistics for AIDS in Africa. The whole story had a quasi-Soviet flavor to it. The main difference: Soviet growth statistics were too good to be true, while African AIDS statistics were too bad to be true. Reflecting on the incentives cemented my skepticism: Just as the Soviet Union had a strong incentive to exaggerate its growth numbers in order to get the world's respect, researchers and advocates had a strong incentive to exaggerate their AIDS number in order to get the world's money.

However, whenever I shared my doubts with others, they almost always told me I was way off-base. Biased statistics about Soviet growth were hard to expose; biased statistics about AIDS would not be.

Now the Washington Post is backing me up:

The new data suggest the rate never reached the 30 percent estimated by some early researchers, nor the nearly 13 percent given by the United Nations in 1998.

The study and similar ones in 15 other countries have shed new light on the disease across Africa. Relying on the latest measurement tools, they portray an epidemic that is more female and more urban than previously believed, one that has begun to ebb in much of East Africa and has failed to take off as predicted in most of West Africa.

Why were the numbers exaggerated for so long?

Such disparities, independent researchers say, skewed years of policy judgments and decisions on where to spend precious health-care dollars.

"From a research point of view, they've done a pathetic job," said Paul Bennell, a British economist whose studies of the impact of AIDS on African school systems have shown mortality far below what UNAIDS had predicted. "They were not predisposed, let's put it that way, to weigh the counterevidence. They were looking to generate big bucks."


"It's pure advocacy, really," said Jim Chin, a former U.N. official who made some of the first global HIV prevalence estimates while working for WHO in the late 1980s and early 1990s. "Once you get a high number, it's really hard once the data comes in to say, 'Whoops! It's not 100,000. It's 60,000.' "

Chin, speaking from Stockton, Calif., added, "They keep cranking out numbers that, when I look at them, you can't defend them."

Still, Peter Ghys, a UNAIDS epidemiologist who now acknowledges that earlier numbers were too high, implausibly chalks the the mistakes up to random error:

Ghys said he never sensed pressure to inflate HIV estimates. "I can't imagine why UNAIDS or WHO would want to do that," he said. "If we did that, it would just affect our credibility."

Can't imagine it? Here's a simple model: People face a trade-off between getting the results they want and protecting their credibility. Sometimes they decide that risking their credibility is worth it - and this was one of those times.

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The author at Acton Institute PowerBlog in a related article titled AIDS: Not that Bad? writes:
    Bryan Caplan at EconLog says that he has long wondered about the validity of the statistics of the spread of AIDS on the African continent: The whole story had a quasi-Soviet flavor to it. The main difference: Soviet growth statistics were too good to be [Tracked on April 10, 2006 11:07 AM]
COMMENTS (11 to date)
T.R. Elliott writes:

Exageration seems common. Remember the missile gape with the Soviet Union? Exageration. Remember Enron and WorldCom's outstanding performance? Exageration. Remember all the great things we were supposed to realize with NAFTA? Exageration. Humans are rational actors? Exageration.

Exageration all over the place.

Jody writes:

I think the exaggeration everywhere phenomenon comes from the fact that advocates have captured the public information process.

English Professor writes:

The Post piece is a welcome bit of honest reporting, but it leaves out as much as it includes. No one in the AIDS community, for instance, explains why the mode of transmission of the disease in Africa appears so different from the mode in the US and Western Europe. In Western nations, the disease still appears to be transmitted primarily through homosexual sex and dirty needles; how is it, then, as the Post story states, that the majority of infected persons in Africa appear to be women? More than 10 years ago I read that there was a new strain of HIV found in Africa that was easily transmitted by heterosexual sex; this was the supposed cause of the rapid spread of the disease. I soon expected the new strain to appear in Europe and America; there would be no way of preventing its spread. But there is no indication that such a strain is ravaging the US. The original report was either incompetent science or pure propaganda intended to mislead Western nations into increasing funding for African AIDS. I suspect it was the UN and WHO propagandizing. The science writer Michael Fumento has been pointing out things like this for years (see, for example, this piece in Tech Central Station last year: ). The mainstream press, though, refuses to investigate.

The questions that I have brought up here are OBVIOUS. Why do no reporters ask them? The misreporting of AIDs statistics has indeed been a shameful episode in the politicization of science, but it is an equally shameful episode in the conduct of modern journalism.

Lisa writes:

I have read that the per diem reimbursement of African doctors and researcher who go to international AIDS conferences equals their yearly incomes. One must do everything in his power to go to such conferences and report results that ensure the conferences continue in the future. Reporting numbers that describe the problem as less than cataclysmic won’t do the trick.

Robert writes:

Those who bother to read the article will find an alternative explanation to Bryan's assumption of data manipulation: the UN's sample population suffered from strong selection effects.

dearieme writes:

In the expression "the AIDS community" you have the key part of the explanation.

Andrew Lasey writes:

Indeed exageration everywhere. Me thinks Bryan exaggerates the level of his skeptism for AIDS in Africa -- this is the first I'm hearing of it.

Hey, I was sceptical of AIDS in Africa, and 1999 Internet stock prices, and Korean cloning research. I'll let you know if a couple years if I'm skeptical of New York City real estate prices.

Robert Speirs writes:

AIDS cases = money for African kleptocracies. That's the explanation for the exaggeration. And the extent and mendaciousness of it can be seen in the percentage of African "AIDS" cases which had never even had a PCR test to detect the virus - 75% 90%? Does anyone really know? Someone is sick, he must have AIDS. Read Kary Mullis "Dancing Naked in the Mindfield" (He won a Nobel Prize for the invention of the PCR test) and, of course, Duesberg, for the flavor.

John Thacker writes:

Mr. Lasey,

Well, Michael Fumento is one person who has been extremely forthcoming with the idea that AIDS in Africa has been exaggerated, at least since 1990. Of course, he's a noted iconoclast and skeptic about lots of similar things, so perhaps he would be expected to.

Joy writes:

I am not shocked to discover that the infection rates of high-risk groups do not exactly translate to the infection rates of the general population. I used to abstract a lot of these studies during the 1990s,and most of the studies at the time were of high-risk or very-high-risk populations. Apparently the idea was to test people who were present (at a clinic) and willing when blood was being drawn, and so mostly the sick and those seeking prenatal care got tested. So very, very many reporters/republishers of these studies fail to note the data collection methods when they summarize results (and as a former abstractor of statistical publications, believe me, this is the FIRST thing I look for when I hear a number cited). After decades of testing pregnant women and STD clinic patients, it's about time they started testing, you know, other people.

The numbers for southern Africa are still shockingly high though.

Andrew Lasey writes:

John Thacker,

I've really enjoy Michael Fumento's writings when I've stumbled across them. As you say he is a noted iconoclast and skeptic. He doesn't seem to come to the party with a strong bias to support.

He also seems to been early to the obesity epidemic issue.

That said, his take on AIDS seems to be that heterosexual transmission in general is exagerated. Where as the washingtonpost article seems to suggest only that the sample used to determine prevalence were high risk urban populations which turned out not to be representative of the whole population. Hardly the same thing. I haven't read Fumento on the issue, but would you agree?


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