Pressure to ban prenatal sex-selection has grown with rising sex ratios at birth in some countries. Governments feel pressured to act, and bans seem an immediate step they can take. However, such bans have been in place for some time in South Korea, China, and India and the available evidence suggests they are difficult to implement and have limited impact. This is indicated most clearly in the Chinese census data, which throw light on the mixed effects of a very intensive effort to implement the ban. Studies show that bans on sex-selection have negative consequences for unwanted girls and their mothers. By contrast, studies show that other policies - including mass messaging and measures to increase gender equity - show fairly quick impact in reducing son preference and increasing parental investment in girls. Such policies can permanently lower son preference and sex-selection, while also improving girls' life-chances.