More Sex is Safer Sex

Economist Steven Landsburg explains why, counterintuitively, the spread of sexually transmitted diseases would decrease if sexually conservative people would start having more sex.

It’s true: AIDS is nature’s awful retribution for our tolerance of immoderate and socially irresponsible sexual behavior. The epidemic is the price of our permissive attitudes toward monogamy, chastity, and other forms of extreme sexual conservatism.

You’ve read elsewhere about the sin of promiscuity. Let me tell you about the sin of self-restraint.

Suppose you walk into a bar and find four potential sex partners. Two are highly promiscuous; the others venture out only once a year. The promiscuous ones are, of course, more likely to be HIV-positive. That gives you a 50-50 chance of finding a relatively safe match.

But what if all once-a-year revelers could be transformed into twice-a-year revelers? Then, on any given night, you’d run into twice as many of them. Those two promiscuous bar patrons would now be outnumbered by four of their more cautious rivals. Your odds of a relatively safe match just went up from 50-50 to four out of six.

It’s true that loosening up will make those “relatively safe” matches a little less safe then they used to be. But that’s easily outweighed by their increased availability.

Of course, the reduced risk of AIDS is an aggregate benefit enjoyed by society whereas the former sexual conservative who provides the benefit actually increases his own risk. He or she would, however, derive the added benefit of increased sexual pleasure.

Hat tip: Courtney Knapp

FILED UNDER: Economics and Business,
James Joyner
About James Joyner
James Joyner is Professor and Department Head of Security Studies at Marine Corps University's Command and Staff College. He's a former Army officer and Desert Storm veteran. Views expressed here are his own. Follow James on Twitter @DrJJoyner.


  1. Jim Durbin says:

    This is a perfect example of how specialization can lead to stupidity.

    Disease transmission follows many natural laws, but economics is not one of them.

    The “recipe” for greater health is more likely to increase the number of infections because it increases the pool of people the promiscuous people sleep with.

    The key to reducing disease transmission is locating the promiscuous people and treating them, or removing them from the greater population.

    The author is attempting a broad description of a generic disease, not applying the specific transmission factors of AIDs or any other disease to the subject. The argument is foolish because it assumes the consequences of increased partners on the behavior of the population as a whole will not change other than the simple addition of a partner. That works on a chalkboard, but not in real life or disease studies.

    The basic idea is disease socialism. Those who are relatively safe should bear more risk to offset the problems of those whose high risk behavior causes the problem in the first place.

  2. James Joyner says:


    He goes into that in the article itself, which is more complicated than the lead-in. He’s not arguing that we shouldn’t treat or otherwise modify the behavior of diseased people or even that increased sexual contact doesn’t increase the risk of individuals. He just notes that, all else held constant, moderate increases in promiscuity would actually substantially reduce aggregate risk of STD acquisition.

  3. me says:

    So if I understand this correctly, the addition in disease rates to otherwise healthy members of society is the price we should pay so that promiscuity can continue with less risk to the promiscuous?

    Or is it that diseased and disease-spreading members of society should be encouraged in avoiding the difficulties caused by their behavior?

    Seems to me like a dog-in-the-manger argument: I can’t use the promiscuous members of society freely, due to disease risk, so let’s make everyone more susceptible to the disease.

    How about this instead: mandatory partner tracking and public identification of HIV positive status. Then rational sex partner choices can be made.

  4. Rodney Dill says:

    Nice. for a one time snapshot in time. Essentially you’re just flooding the market with “safe partners,” but as they and you continue with promiscuity the percentage chance of infection would contine to rise (and in the example given at an even faster rate.) You’ve only effectly reset the current base infected level.

  5. Jim Durbin says:

    I did read through his description – but his point is that in a “laboratory setting,” with no changes in the behavior patterns of people and without a time limit and without transmission factors, STD’s would slow down. It’s simply not how it works in the real world.

    Disease transmission stops when it hits monogamous couples, precisely because they don’t infect new partners.

    Assuming 100% transmission (impossible), the number of new infected people would remain the same, because there are only a few truly promiscuous people out there.

    Increasing the pool increases the number of people with an STD, which is why STD rates of infection increase in Baltimore in the summer as teenagers and others flock to the beaches and engage in more sex.

    The Tipping Point has some great information on this.

    But the real problem is the purpose of the article in book is an example of junk science. It’s only purpose is to show how people’s perception of what is right and wrong doesn’t match with scientific fact. My proof for this is the casual attitude taken towards monogamy by Steven.

    I don’t think he’s actively suggesting that the general public should have more sex. I think he’s suggesting that the wisdom of monogamy is counterproductive to Society as a whole, and a relic of unthinking monogamists.

    He’s placing science in opposition to morality. And he”s wrong. The two complement each other in his example. Monogamy is good for Public Health.

  6. Jim Durbin says:

    And in the long run, we are all dead.

    Sorry, just a little economic joke.

    The point is just silly. It’s like saying if a killer is on the loose with six bullets in a gun, increasing the number of people on the street lowers the risk for the group as a whole. How is that interesting without the sex angle?

  7. As a *non-promiscuous* person with an STD, I found the article to be exactly what it is: junk science. Jim is correct in saying the only way to put a stop to STD transmission is for the infected to be monogamous, preferably with others who are infected as well. Being “dead ends”. Sounds easy, right? Not exactly. I know.

    But with bitterness aside: Pitting science against morality does wonders for society. Seeing scientific, mathematical proof concerning ourselves demands for us draw up new game plans to rethink what is morally just and often serves as a slap in the face.

    The bottom line is that bad things happen to good people, regardless.

    Isn’t is disturbing that every move we make in society is a game of Russian roulette?