Over the next few decades, world fertility levels are projected to continue a dramatic decline, leading to a deep reduction in previously expected levels of world population. In modern countries, fertility is already below the "replacement level" of 2.1 children per woman; the developing world will follow. The potential implications for commerce, pensions, the environment, and geopolitics are enormous.

Ben J. Wattenberg, a senior fellow at AEI, is the moderator of the PBS program Think Tank with Ben Wattenberg and the author of ten previous books, including The Birth Dearth (1989).