Forty years ago, the countries of East and Southeast Asia were among the most densely populated in the world. In most countries of the region, natural resources were limited, populations were growing, and standards of living were low. Few observers were optimistic about the region’s development prospects. Beginning in the 1960s, however, several East and Southeast Asian countries adopted and vigorously pursued policies that have successfully slowed population growth and accelerated economic development. The experience of six Asian countries—Japan, South Korea, Taiwan, Singapore, Thailand, and Indonesia—provides strong evidence that economic gains can be achieved by lowering rates of childbearing. Between 1960 and 1990, childbearing and population growth rates dropped steeply in these countries. During the same period, all six countries also achieved unparalleled economic development, progressing from poverty to catch up with, or even surpass, the high-income countries of the West. But did demographic change in general— and population policies in particular—play an important role in achieving economic success?