The 2015 Millennium Development Goal to reduce by 50 percent the share of the world’s population living in extreme poverty was met early. The number of individuals in developing countries who live in extreme poverty had decreased from 43 percent in 1990 to 21 percent by 2010. Yet, with 1.2 billion people still struggling today, we have a long way to go. What can we learn from the recent success of reducing extreme poverty? Understanding Changes in Poverty brings together different methods to decompose the contributions to poverty reduction. A simple approach quantifies the contribution of changes in demographics, employment, earnings, public transfers, and remittances to poverty reduction. A more complex approach quantifies the contributions to poverty reduction from changes in individual and household characteristics, including changes in the sectoral, occupational, and educational structure of the workforce, as well as changes in the returns to individual and household characteristics.