The pace and scope of economic development continues its rapid, uneven, and sometimes unexpected evolution. This text explains the unprecedented progress that has been made in many parts of the developing world—but fully confronts the enormous problems and challenges that remain to be addressed in the years ahead. The text shows the wide diversity across the developing world, and the differing positions in the global economy held by developing countries. The principles of development economics are key to understanding how we got to where we are, and why many development problems are so difficult to solve; and to the design of successful economic development policy and programs as we look ahead