Book review: “More than 160 million females are “missing” from Asia’s population. That’s more than the entire female population of the United States. Gender imbalance—which is mainly the result of sex selective abortion—is no longer strictly an Asian problem. In Azerbaijan and Armenia, in Eastern Europe, and even among some groups in the United States, couples are making sure at least one of their children is a son. So many parents now select for boys that they have skewed the sex ratio at birth of the entire world. In her first book, Unnatural Selection: Choosing Boys Over Girls, and the Consequences of a World Full of Men, Mara Hvistendahl explores how this has occurred, asking why women and girls are becoming scarce in Asia and Eastern Europe as these regions develop, and what will happen when the world’s extra boys grow up. Drawing on extensive reporting in China, India, Vietnam, South Korea, Albania, and other countries, Hvistendahl weaves together the story of the world’s “missing” women into a riveting narrative, casting everyone from prostitutes, mail-order brides, and militant nationalists to geneticists, activists, and AIDS researchers—along with the California fertility doctors hard at work selling the world’s parents on the latest form of sex selection. In this discussion, she delves into the implications for security, women’s rights, governance, and economic development.”