Indonesia, the world’s fourth most populous country, cut its fertility rate in half over a 30-year period. After decades of international efforts administered by the United Nations, development experts concur that family planning programs have been a key tool in reducing poverty and in empowering women—an undisputed path to development for poor countries. Indonesia’s policy, which aimed to limit families to two children, has reduced fertility rate to 2.37 births per woman in 2012. The centralized policy extended maternal health and family planning clinics across this nation of 255 million people, leading to a sharp dip in maternal mortality. Challenges remain for Indonesia, and many other countries. Here’s an in-depth look at what we can learn from Indonesia.