Does rapid population growth diminish countries' economic development prospects? Do policies aimed at reducing high fertility help families escape poverty? These questions have been at the heart of policy debates since the time of Malthus, and have been particularly heated during the last half-century of explosive Third World population growth. In this carefully constructed collection of recent studies and analyses, the authors offer a nuanced, yet clear and positive answer to these questions---a refreshing step forward from the ambiguous conclusions of much of the literature of the 1970s and 1980s.