An investigation of the timing pattern of childbearing

Abstract

This paper reports an investigation of the relation between the number of live births during a woman's reproductive life-cycle and her ages at those births. Four samples of women from the United States and from the Philippines are used. The timing patterns of childbearing in these samples display several striking regularities. In all samples childbearing tends to occur in the centre of the fecund period irrespective of the number of children, so that the mean age at childbearing is essentially independent of final parity. In addition, the timing patterns are symmetric around the mean age at childbearing. Most important of all, the patterns are very alike in the different samples examined, despite large differences between average family size, methods used to regulate fertility, and economic, social, and cultural characteristics in the different populations.

This paper extends considerably a brief examination of the structure of childbearing (based only upon a sample of the U.S. White population) which was contained in my doctoral disseration (see L.E. Edlefsen, ‘The Joint Determination of the Numbers, Timing, and Spacing of Births’, Ph.D. dissertation, Harvard University, 1978). A previous version of this paper was entitled ‘The Fundamental Structure of Fertility’. The current research was supported by a grant from the Graduate School Research Fund at the University of Washington. I am indebted to the able research assistance of Prapan Tianwattanatada, in preparing the data tapes and in helping with the analysis, and of Terry Wayment in helping with the preparation of the figures. I have benefited from the helpful comments of Masanori Hashimoto, Samuel Lieberman, Sam Preston, Tom Pullum and Nicole Urban on earlier drafts. I would like to thank Dr Mercedes Concepcion, Dean of the Population Institute at the University of the Philippines for permission to use the 1973 Philippine National Demographic Survey.

This paper extends considerably a brief examination of the structure of childbearing (based only upon a sample of the U.S. White population) which was contained in my doctoral disseration (see L.E. Edlefsen, ‘The Joint Determination of the Numbers, Timing, and Spacing of Births’, Ph.D. dissertation, Harvard University, 1978). A previous version of this paper was entitled ‘The Fundamental Structure of Fertility’. The current research was supported by a grant from the Graduate School Research Fund at the University of Washington. I am indebted to the able research assistance of Prapan Tianwattanatada, in preparing the data tapes and in helping with the analysis, and of Terry Wayment in helping with the preparation of the figures. I have benefited from the helpful comments of Masanori Hashimoto, Samuel Lieberman, Sam Preston, Tom Pullum and Nicole Urban on earlier drafts. I would like to thank Dr Mercedes Concepcion, Dean of the Population Institute at the University of the Philippines for permission to use the 1973 Philippine National Demographic Survey.

Notes

This paper extends considerably a brief examination of the structure of childbearing (based only upon a sample of the U.S. White population) which was contained in my doctoral disseration (see L.E. Edlefsen, ‘The Joint Determination of the Numbers, Timing, and Spacing of Births’, Ph.D. dissertation, Harvard University, 1978). A previous version of this paper was entitled ‘The Fundamental Structure of Fertility’. The current research was supported by a grant from the Graduate School Research Fund at the University of Washington. I am indebted to the able research assistance of Prapan Tianwattanatada, in preparing the data tapes and in helping with the analysis, and of Terry Wayment in helping with the preparation of the figures. I have benefited from the helpful comments of Masanori Hashimoto, Samuel Lieberman, Sam Preston, Tom Pullum and Nicole Urban on earlier drafts. I would like to thank Dr Mercedes Concepcion, Dean of the Population Institute at the University of the Philippines for permission to use the 1973 Philippine National Demographic Survey.