If you give U.S. tax dollars to a Mexican male prostitute, will he agree to stay disease-free? That’s what government-funded researchers at Brown University would like to know.

The study is called “Conditional Economic Incentives to Reduce HIV Risks: A Pilot in Mexico,” and uses a grant from the National Institute of Health to pay male prostitutes in Mexico City. The prostitutes were placed in different groups and tested for sexually transmitted diseases. For every six months that they remain clean, they receive a payment that is larger or smaller depending upon their group.

Though the dollar amounts paid to each prostitute are small — they must remain poor enough to continue in prostitution, of course — the study has already cost nearly $400,000.

Researchers hope the experiment will show that financial incentives can be used to deter the spread of HIV/AIDS.

But Drew Johnson of the Center for Individual Freedom wondered if bribing Mexican prostitutes was the best use of the taxpayer’s dime.

“At a time when the federal government is hiking taxes, raising its debt ceiling and drowning in ever-deepening debt, the last thing Washington needs to do is ship our money to Mexico City to give a cash reward to prostitutes for not catching Chlamydia or Gonorrhea,” he wrote. “But that’s not stopping them.”

The study’s leader is Omar Galarraga, an assistant professor of health policy at Brown. He did not respond to a request for comment.

Brown’s website praises the study’s “innovative structural approach.”

Brown is not the only university spending public money investigating the sexual diseases of Mexican prostitutes; the University of California at San Diego has received $3 million from the NIH in order to study infection rates.

The UC-San Diego study does not involve paying prostitutes, however.

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