An analysis of the hypothesis that the frequency of births in a population can be understood in terms of three factors that influence the desire for births: (1) a family size goal that is determined by characteristics of the environment; (2) the incidence of death among offspring; and (3) the effect of uncertainty in the family formation process. The hypothesis implies that these factors determine the average level of preferred birth rates and that they exert a systematic effect on actual births in following periods. These implications are tested by empirical evidence from Puerto Rico for the 1890s and 1950s by juxtaposing birth rates and environmental variables that include mortality, education, and the economic activity of women and children. The association between birth rates and environmental variables is consistent with the implications of the hypothesis. Other factors that are not accounted for by the family planning model are also considered as sources of variation in birth rates: urbanization, agricultural activity, age/sex, and marital status. These factors do not emerge as significant when the other variables of the family planning model are also considered.
This report is part of the RAND Corporation Research memorandum series. The Research Memorandum was a product of the RAND Corporation from 1948 to 1973 that represented working papers meant to report current results of RAND research to appropriate audiences.
This research in the public interest was supported by RAND, using discretionary funds made possible by the generosity of RAND's donors, the fees earned on client-funded research, and independent research and development (IR&D) funds provided by the Department of Defense.
This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit www.rand.org/pubs/permissions.
The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.