Small point of order from watching the video (it'll make sense when you get there):

South Korea Bounces Reign of Baby Boys:

Shedding an age-old preference for sons, South Korea has in the last two decades become the first Asian country to reverse a large sex imbalance at birth. A radical shift in Koreans' attitude toward female babies—and toward working women—has brought down the rate of sex-selection abortion, the New York Times reports.

Sons were once viewed as a form of retirement insurance, while daughters were married off to serve their husbands' families. But thanks to economic changes, what Korean parents most want from their children in old age is now emotional rather than economic support—something daughters are seen as better at providing. Observers hope South Korea can provide a model for China and India, where abortion of female fetuses is rampant.

Korea had too many boys... and then they started wanting girls rather than boys.