Chinese parents value firstborns regardless of sex

The existence of families with more than one child has allowed researchers to track the practice of sex selection before birth, particularly since hard data on abortion and infanticide is scarce.

Health policy expert Avraham Ebenstein of Harvard University examined China's 2000 census data and found that the sex ratio of first births for couples was close to the natural sex ratio, but it became increasingly skewed following the birth of one or more daughters. That suggests parents value firstborns regardless of sex, but practice sexual selection for later children if they do not yet have a boy. 'The steep rise in sex selection rate between first and second births is responsible for 70 percent of missing girls,' Ebenstein says.