This week, the Bill and Melinda Gates Foundation released their annual letter, all about the myths that block progress for the poor. Economic development is a complicated puzzle, and there are no easy solutions. But as the letter points out, there are things we can do — and things that many in developing countries are already doing — to fight poverty and encourage growth.

One of these that often gets overlooked, and that has also become a signature issue for Melinda Gates, is family planning. Right now, 222 million, or one in four women of reproductive age in the developing world, do not want to become pregnant, but need modern contraception.