If a girl in a poor country goes to school, she will probably have a more comfortable life than if she stays at home.
She will be less likely to marry while still a child, and therefore less likely to die in childbirth.
So, not surprisingly, there is an Indian charity that tries to get girls into school and ensure they learn something,
and there are Western philanthropists willing to pay for its work. What is noteworthy is how they have gone about this transaction.
On July 13th the Brookings Institution, a think-tank, presents the results of the world's first large development-impact bond,
which paid for girls' education in the northern Indian state of Rajasthan.
In this novel way of funding charitable work, a financial institution gives money to a charity, which tries to achieve various specified outcomes.
If a neutral arbiter rules that it has succeeded, a donor or philanthropist repays the investor, plus a bonus.
If it fails, the investor loses some or all of its money.
This is more convoluted than the usual way of funding charitable projects,
in which a donor gives money to a charity, which spends it according to a pre-agreed plan.
The donor tries to ensure the money is not wasted by keeping track of inputs-the number of solar panels installed or vaccinations given, say.
Often, no one knows whether the intervention did much good.
In this case, the more complicated approach did achieve something.
Educate Girls, the charity, identified 837 out-of-school girls aged 7-14 in the villages where it was active, and enrolled 768 of them.
By using volunteers to teach both boys and girls in village schools for a few hours a week,
it managed to raise test scores substantially relative to a control group.
So the investor, UBS Optimus Foundation, will be repaid by the Children's Investment Fund Foundation.