Case for Promiscuity!

I have been reading one of Steven Landsburg's articles on Slate, "More Sex is Safer Sex"
Here is a case made out for promiscuity! It is a delightful read and contends that excessive abstinence can be a double-edged sword, in so far as it could leave the market open to be captured by the more reckless and potentially AIDS infected partners. Sample this:

"If multiple partnerships save lives, then monogamy can be deadly. Imagine a country where almost all women are monogamous, while all men demand two female partners per year. Under those conditions, a few prostitutes end up servicing all the men. Before long, the prostitutes are infected; they pass the disease to the men; and the men bring it home to their monogamous wives. But if each of those monogamous wives was willing to take on one extramarital partner, the market for prostitution would die out, and the virus, unable to spread fast enough to maintain itself, might die out along with it."

Landsburg analyses the market inefficiency thus,
"To an economist, it's clear why people with limited sexual pasts choose to supply too little sex in the present: Their services are underpriced. If sexual conservatives could effectively advertise their histories, HIV-conscious suitors would compete to lavish them with attention. But that doesn't happen, because such conservatives are hard to identify. Insufficiently rewarded for relaxing their standards, they relax their standards insufficiently. So a socially valuable service is under-rewarded and therefore under-supplied."

The articles goes on to suggest that the only way in which sexually prudent behaviour can be encouraged, without at the same time promoting irresponsible predations, is to subsidize or even supply condoms free of cost.