Saturday, April 01, 2006

Do People Respond To Incentives?

This New York Times article suggests that demand curves do slope down! People engage in less risky behavior when the "price" of such behavior increases. Experts appear to be surprised by this good news. Could Peak Oilers learn something from this seemingly unrelated example?

March 31, 2006
New H.I.V. Cases Reported to Drop in Southern India

In a rare piece of good news about AIDS, the prevalence of new H.I.V. infections has fallen significantly in southern India, the region of that country where the disease has occurred most often, scientists reported yesterday.

Many health officials have predicted major increases in H.I.V. in India, which has the world's second highest number of infected people, after South Africa. But new infections among young adults declined by more than a third from 2000 through 2004, according to a statistical study by Dr. Rajesh Kumar and a team of researchers reported in the journal Lancet.

The findings seem real and not due to statistical aberrations, the authors said. They are from academic centers and a government health institute in India, the University of Toronto and the United Arab Emirates.

The authors attributed the favorable trend to an increasing use of condoms by men and an insistence by prostitutes that their partners use them. That decline, in turn, reduced the transmission of H.I.V. to spouses.

Experts cautioned against drawing too firm a conclusion from one study and added that the new findings did not mean India's H.I.V. epidemic was over.

Still, the study has two key implications, the researchers said.

One is that strategies that emphasize education about how H.I.V. can be transmitted and the use of condoms offer the best hope for reducing the spread of the virus in India.

A second is that routine monitoring of H.I.V. and other sexually transmitted diseases are powerful and cost-effective ways to control AIDS in India. But experts urged constant vigilance for signs of a reversal of the favorable trend.

The findings were based on test results from 294,050 women who attended 216 prenatal clinics and 58,790 men attending 132 clinics for sexually transmitted diseases.

The prevalence of H.I.V. among women aged 15 to 24 in the southern states fell to 1.1 percent from 1.7 percent during the period of study. But H.I.V. prevalence did not fall significantly among women aged 25 to 34.

Epidemiologists often analyze the rate of H.I.V. among pregnant women because they consider it an indication of its prevalence in the general population.

The study showed that the prevalence of H.I.V. fell in men aged 20 to 29 in the southern states.

Reductions were more modest in 14 northern states, where the prevalence of H.I.V. infections is about one-fifth that in the four southern states, the authors said.

About 75 percent of the estimated 5.1 million Indians with H.I.V. live in the four southern states, Andhra Pradesh, Karnataka, Maharashtra and Tamil Nadu.