Though everyone has an equal right to education, girls and women lag far behind boy and men. Two out of three of the 110 million children in the world who do not attend school are girls - and there are 42 million fewer girls than boy in primary school. Even if girls start school, they are far less likely to complete their education. Girls who miss out on primary education grow up to become the women who make up two-thirds of the world’s 875 million illiterate adults.

Sub-Saharan Africa, South Asia, Middle East and North Africa have the widest gender gaps. A six-year-old girl in South Asia will typically spend six years in school, compared with nine years for a boy. Living in the countryside widens the gap; a girl living in a rural area is three times more likely to drop out of school than a city boy.

Yet education is not only their fundamental right, but an effective way of achieving higher economic growth as well as social well-being. Educated girls marry later, have fewer children, and feed and look after themselves and their family better. Their survival rate is higher, and their daughters are themselves more likely to go to school. Studies have shown that women with some education are more productive than those with none, for example in agriculture.