The chapter discusses the economic analysis of fertility, focusing on the relationship between income and fertility. The author, Gary S. Becker, argues that the decline in birth rates in the postwar period has made it difficult to predict future trends accurately, leading to a need for a more sophisticated analysis. He suggests that fertility decisions are influenced by both economic and non-economic factors, but the economic framework is particularly relevant. Becker's analysis is based on the assumption that families have perfect control over the number and spacing of their births, and that children are treated as a consumption good. He posits that the demand for children is influenced by tastes, income, and the quality of children. The quality of children refers to the resources and attention parents allocate to each child, which can vary with income. Becker argues that an increase in income should lead to both an increase in the quality and quantity of children, but the quantity elasticity is likely small. The chapter also examines empirical data from various studies, including the Indianapolis survey and census data, to test the theoretical framework. The data suggests a negative relationship between income and fertility, which can be explained by differential knowledge of contraceptive techniques and changing tastes. However, Becker notes that this relationship is not always consistent, and other factors such as child mortality, contraceptive knowledge, and the cost of children may also play a role. Finally, the chapter discusses the implications of the economic analysis for understanding temporal fluctuations in births and the impact of economic conditions on fertility. It highlights that births are "flows" to the "stock" of children, and that economic conditions can affect both the flow and the stock of children. The analysis provides a framework for understanding how economic changes can influence fertility patterns.The chapter discusses the economic analysis of fertility, focusing on the relationship between income and fertility. The author, Gary S. Becker, argues that the decline in birth rates in the postwar period has made it difficult to predict future trends accurately, leading to a need for a more sophisticated analysis. He suggests that fertility decisions are influenced by both economic and non-economic factors, but the economic framework is particularly relevant. Becker's analysis is based on the assumption that families have perfect control over the number and spacing of their births, and that children are treated as a consumption good. He posits that the demand for children is influenced by tastes, income, and the quality of children. The quality of children refers to the resources and attention parents allocate to each child, which can vary with income. Becker argues that an increase in income should lead to both an increase in the quality and quantity of children, but the quantity elasticity is likely small. The chapter also examines empirical data from various studies, including the Indianapolis survey and census data, to test the theoretical framework. The data suggests a negative relationship between income and fertility, which can be explained by differential knowledge of contraceptive techniques and changing tastes. However, Becker notes that this relationship is not always consistent, and other factors such as child mortality, contraceptive knowledge, and the cost of children may also play a role. Finally, the chapter discusses the implications of the economic analysis for understanding temporal fluctuations in births and the impact of economic conditions on fertility. It highlights that births are "flows" to the "stock" of children, and that economic conditions can affect both the flow and the stock of children. The analysis provides a framework for understanding how economic changes can influence fertility patterns.