Julia Lovell in The Guardian:
The book's title is drawn from a vile state-sponsored media campaign of the same name, which is designed to browbeat educated, professional women into early marriages in the interests of safeguarding social stability. Since at least 2007, newspapers, magazines, websites and – perhaps most troublingly of all – the All-China Women's Federation (a government organisation founded in 1949 supposedly to defend women's rights) have aggressively pushed the idea that unmarried urban females over 27 are “leftover women”. These women may have university degrees and thriving careers but in the eyes of much of the state-controlled media they are essentially worthless without husbands and children. “Do leftover women really deserve our sympathy?” asked one article on the Women's Federation website. “Girls with an average or ugly appearance … hope to further their education in order to increase their competitiveness. The tragedy is they don't realise that, as women age, they are worth less and less, so by the time they get their MA or PhD, they are already old, like yellowed pearls.
More here.