Economists, demographers and other social scientists have long debated the relationship between demographic change and economic outcomes. In recent years, general agreement has emerged to the effect that improving economic conditions for individuals generally lead to lower birth rates. But, there is much less agreement about the proposition that lower birth rates contribute to economic development and help individuals and families to escape from poverty. The paper examines recent evidence on this aspect of the debate, concludes that the burden of evidence now increasingly supports a positive conclusion, examines recent trends in demographic change and economic development and argues that the countries representing the last development frontier, those of Sub-Saharan Africa, would be well advised to incorporate policies and programmes to reduce high fertility in their economic development strategies.