Isegoria

Tyler Cowen cites some recent research that answers the question, How many children should you have?:

In comparing identical twins, Kohler found that mothers with one child are about 20 percent happier than their childless counterparts; and while fathers’ happiness gains are smaller, men enjoy an almost 75 percent larger happiness boost from a firstborn son than from a firstborn daughter. The first child’s sex doesn’t matter to mothers, perhaps because women are better than men at enjoying the company of both girls and boys, Kohler speculates.

Interestingly, second and third children don’t add to parents’ happiness at all. In fact, these additional children seem to make mothers less happy than mothers with only one child — though still happier than women with no children.

Tyler Cowen summarizes Justin Wolfers and Betsey Stevenson, whose research says that Matrimony Has Its Benefits, and Divorce Has a Lot to Do With That:

In the United States, the availability of divorce has increased with unilateral divorce, which allows either member of the couple to dissolve the union. The change has been associated with lower rates of female suicide and domestic violence, and fewer wives murdered by their husbands. Unilateral divorce shifts the bargaining power to the person who is getting less out of the marriage and thus is most likely to leave. The partner getting more from the marriage has to work harder to keep the other person around, which can be good for the marriage and good for the couple. In other words, unilateral divorce benefits victims and potential victims.

When unilateral divorce was adopted, divorce rates rose sharply in the two years that followed, reflecting a pent-up demand for divorce. But after 10 years had passed, the divorce rate went back to normal or in some cases, compared with states without unilateral divorce, it had fallen further.

In fact, the divorce rate for married couples peaked in the United States in 1979, when it was 22.8 per thousand married couples per year. Since then it has continued to decline, reaching 16.7 divorces per thousand married couples in 2005.

Bryan Caplan, who has a new book out, speaks in praise of his competition, Steve Landsburg. Landsburg’s new book bears the risqué-yet-Freakonomics-esque title, More Sex is Safer Sex, and its title essay demonstrates the power of model-building in an unusual problem domain:

Imagine a country where almost all women are monogamous, while all men demand two female partners per year. Under those circumstances, a few prostitutes end up servicing all the men. Before long, the prostitutes are infected; they pass the disease on to the men; the men bring it home to their monogamous wives. But if each of these monogamous wives were willing to take on one extramartial partner, the market for prostitution would die out, and the virus, unable to spread fast enough to maintain itself, might well die out along with it.