In South Asia and sub-Saharan Africa 38% of women marry before they are 18 years old. Child marriages, as defined by UNICEF, the United Nations’ children’s agency, are those undertaken by women under the age of 18 and include unions where a woman and a man live together as if they were married.

According to a UNICEF , most child marriages take place between the ages of 15 and 18, but in three countries, Niger, Chad and Bangladesh, more than a third of women aged 20-24 were already married by the age of 15. Such practices often flout the law: whilst the legal age of marriage in India is 18 around half of the Indian women surveyed were already married by that age. One negative effect of early marriage is the exclusion of women from education in favour of domestic work and child rearing. So countries with a high prevalence of child marriages also tend to have low literacy rates for young women.