Want to reduce births by teenage girls? Increase the legal age when students can drop out of school, say three economists who have studied the impact of compulsory education laws in the United States and Norway.
The economists found that requiring students to stay in school until at least 16 years old reduces the chances that a woman will give birth before turning 20 by 4.7 percent in the United States. Increasing the age when students can leave school to 17 nearly doubles the effect, reducing the probability of teen births by 8.8 percent.
Similar results were obtained in their study of teen births in Norway, where the mandatory school age was raised from 14 to 16 in the 1970s, wrote Sandra E. Black and Paul J. Devereux of UCLA and Kjell G. Salvanes of the Norwegian School of Economics and Business Administration in a working paper published by the National Bureau of Economic Research.
They based their conclusions on census data collected between 1960 and 1980 in both countries. During that time, about 4 percent of the women in the U.S. sample lived in states where the dropout age was 15 or younger, 75 percent in states with a minimum age of 16, about 12 percent in states where it was 17 and 9 percent where they had to stay until they turned 18. About one in six of these women -- 17 percent -- had their first child when they were in their teens.
The researchers wanted to know why staying in school cut the teen birth rate. Was it because students didn't have time for sex? "We call this the 'incarceration effect'; while women are in school, they do not have the desire/time/opportunity to have a child," they wrote.
But when they looked, they found no evidence of such an incarceration effect, either in the United States or in Norway.
Instead, they suspect that an additional year or two in school -- even forced schooling -- may increase the chances that a woman or man will make better decisions.
"The additional schooling may make you 'smarter' and hence decide to postpone childbearing," they wrote.
Truth in Sizing
Anyone looking for evidence to support Albert Einstein's theory of relativity needs to go no further than the racks in any women's clothing store, where pants labeled as size 8 can be anywhere from a size 4 to 14, depending on the manufacturer and how much the garment costs.
At least that's what Tammy R. Kinley of the University of North Texas School of Merchandising found when she and a team of researchers meticulously measured a total of 1,011 pairs of women's pants in different sizes from different manufacturers at 20 retail stores in Texas.
Women, you can guess what they found: Huge variations in garments that purportedly were all the same size, Kinley reported in a recent issue of Clothing & Textiles Research Journal.
Some of the discrepancies defied belief. Kinley measured the waist circumference of 139 pairs of pants labeled "Size 4" and found that they differed by nearly nine full inches, from a petite 23 inches to a decidedly super-size 31 1/2 inches. She found the same thing in 170 pairs of size 10 pants, where the difference ranged from 27 to 34 inches. And size 14 pants varied from slightly more than 30 inches -- smaller than some manufacturers' size 4 -- to a generous 38 inches. In all six sizes studied, from 4 to 14, the range of variation in waist circumference was never smaller than 6.2 inches. Similar disparities surfaced when her research team measured the dimensions of the inseam and crotch seam of each pair of pants.
The problem is that manufacturers of women's clothes have great leeway in determining exactly what is a size 8. There are, of course, government guidelines -- largely developed in the 1940s after a large-scale measuring survey of 15,000 women conducted by the Department of Agriculture's National Bureau of Home Economics. But in garments produced for the mass market, those standards are honored more in the breach than in the observance, Kinley said.
For years women have been wary of size labels, based on bitter experience. Variations in sizing is the leading reason why many women are hesitant to shop for clothes over the Internet. But serious attempts to document the differences in sizing are few and far between -- until now, Kinley said.