For more than 200 years, ever since the Revd Thomas Malthus produced his famous First Essay on Population, scholars and intellectuals have been debating the question of whether population growth inhibits improvements in the social and economic conditions of societies. The debate acquired special urgency in the second half of the twentieth century as population growth reached rates higher than had ever been previously recorded in country after country, and policy-makers demanded to know whether or not they should intervene directly. Unfortunately, scientific research has not provided particularly useful guidance to policy over the last half century. Practitioners of the various disciplines differed strongly among themselves and produced widely divergent, often contradictory advice to policy-makers. The part that follows traces some of the history of recent debates between economists and members of other disciplines, and among economists themselves. Birdsall and Sinding summarize the principal conclusions that emerged from the symposium from which this book derives. Foremost among the findings is a shift in the view of most economists who have studied the demographic/economic development relationship in recent years-from a view that the relationship is neutral to mildly negative to one that finds considerable evidence that high fertility often inhibits growth and that successful efforts to reduce fertility can accelerate economic development. Allen Kelley traces the evolution of academic inquiry on the significance of population growth for development, from alarmism to what he calls 'revisionism' , to a more nuanced form of revisionist thought-from the 1950s and 1960s population crisis mentality, to the 1980s view that population growth is a 'neutral' phenomenon, to the contemporary view (which is encapsulated in the title of this book) that population does matter. He points out that the key factor distinguishing the various assessments is the time period over which population impacts are assessed. The impacts highlighted during the 'alarmist period' were distinctly direct, and short run, in which demographic impacts are relatively strong. The impacts during the 'neutralist' period were long run in focus, allowing time for adjustments and feedbacks to occur. Demography had smaller roles in this time frame. In the 1990s, an intermediate time perspective is adopted-a few decades of the demographic transition-so the impacts found, not surprisingly, are somewhere in between: population does matter, but it is not all determining, nor can or should it be ignored. John Bongaarts helps to lay the groundwork for understanding why population matters by explaining the rapid shifts in dependency burdens that occur during the transition from high to low mortality and fertility. Early in the transition, populations are very young and the size of the young age cohort (under age 15), compared to the economically active one (15-65), is very large. At the middle stages of the transition, as fertility falls, the proportions begin Set...