Married off at very young ages, less prized than boys, victims of sex trafficking, and very much excluded from education, girls are the most vulnerable group in the developing world. There, 66 million girls find themselves out of school, either because their family can’t afford to send them, or because their role is seen to be in the home or working.

A new film explores the lives of 9 young girls from across the developing world. It argues that investing in young girls’ education is the key, not only to enriching their lives, but to eradicating poverty.

Richard Robbins is director of "Girl Rising," and Holly Gordon is executive director of 10x10, a global campaign to educate and empower girls.