Sex selection of children, which results in imbalances in the ratio of males to females in a given society, is known to be a common practice in Asian countries like China and India. But this practice is not only a problem in Asia: it has also led to dramatic discrepancies in the birth ratio of boys to girls in the Caucasus. Indeed, in a recent paper, NYU Abu Dhabi Assistant Professor of Social Research Marc Michael found that sex selection in Armenia, Azerbaijan, and Georgia has resulted in birth ratios that exhibit imbalances that are greater than or equal to those of China or India.

Males are naturally born at a higher rate than females — 105 males to 100 females. It is thought that this imbalance is an evolutionary development, as more boys die in childhood from disease and accident than do girls. Thus, by the time of puberty, the ratio of males to females is equal.

But in Armenia and Azerbaijan, the birth ratio was more than 115 males to 100 females from 2005 to 2009. And in Georgia the birth ratio was more than 120 males to 100 females during the same period.

"Overall, the number of girls born in these countries in 2010 was 10 percent lower than expected, consistent with 1,972 sex-selective abortions in Armenia and 8,381 in Azerbaijan," Michael found.

Technological developments have facilitated the practice of sex selection for families in former-Soviet republics. "The increases in sex ratios at birth in the Caucasus appear to have coincided with the importation of cheap portable ultrasound machines after the collapse of the Soviet Union," Michael writes.

But technology alone can't fully account for the imbalance in the Caucasus. To control for technological advances, Michael analyzed birth data of other Soviet bloc countries — Kazakhstan, Moldova, and Ukraine, for example — that experienced a similar inflow of Western technology in the years following the Soviet collapse. Unlike the Caucasus, however, these countries did not exhibit an imbalance in male births.

Michael argues that a possible explanation for the gender imbalance in Armenia and Azerbaijan may be that those countries "have been involved in so-called frozen wars — protracted, violent ethnic conflicts that have occasionally intensified into prolonged states of insecurity." These conflicts "might greatly diminish women's bargaining powers in the public and private spheres, such that men's preference for sons determines couples' reproductive and family planning practices."

In order to more fully understand the birth imbalance in the Caucasus, future research must focus on understanding the "social dynamics of female devaluation and son preference," Michael concluded.