Living in Sin

If President Bush wants to promote marriage he might want to look at Sweden in the late 1980's. Here's a graphic showing marriages by month from a new paper by Anders Björklund and Marianne Sundström of Stockholm University and Donna K. Ginther of the University of Kansas.

The number of newlyweds zoomed to 64,000 in December 1989 from an average of 3,000 in Decembers past -- a 20,000 percent increase! The new-found desire to commit can be attributed to one motivating force: money.

The previous year, Sweden changed its pension system to phase out widows' pensions. The change meant that after 1990, the amount of money available to widows (and certain women who lived long-term with their boyfriends) was drastically reduced. But if you were married before 1990 you could hold on to the old pension scheme. So with old-age looking less secure, thousands lined up to get hitched before the deadline.

While this last point only applied to women born before 1945, a "bandwagon-effect" took place. Many women who were not eligible to get a full widows' pension upon their husbands' death -- even if they were married before 1990 -- still decided to tie the knot. (Why did this bandwagon-effect exist? The researchers attribute it to bad information about who was eligible disseminated by the press.)

This is all a belabored way to get to the point of the researchers study: Do children who live with married parents perform better in school than those with parents who cohabitate but haven't tied the knot?

The three researchers looked at a random sample of all children born in the 1970's and 80's and compared their G.P.A.s at age 16. They initially found that there indeed was a correlation between achievement and the timing of marriage: children whose parents were married before they were born did better than other types of children.

But the achievement gap disappeared when the researchers looked only at children whose parents married in the fall of 1989 (in response to the financial incentives) compared to children who parents stayed unmarried.

To investigate further, the researchers looked at the G.P.A.'s for children from the two types of marriages that occurred at the end of 1989: those who really qualified for the widow's pension (i.e., had a clear incentive for getting married), and the bandwagon sample (i.e. those without a financial incentive).

There is one major caveat for the study: Sweden has the highest level of cohabitation in the developed world, so the results could be different for a country with a less accepting culture.

One argument for marriage is that it allows parents to split up the duties involved in rearing a child. It's a lot easier for two people to coordinate the feeding, education and physical activity of a child than for one parent to do it alone. But is marriage absolutely necessary for this to happen, and, if so, should governments promote it?

Our results provide bad news for policy-makers who seek to enact policies to promote marriage. For marriage to have a positive impact on child outcomes, it seems necessary that parents marry because they want to, not because they respond to a policy incentive.