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Lam, David, Jeffrey A. Miron, and Ann Riley. 1994. "Modeling Seasonality in Fecundability, Conceptions, and Births." Demography, 31(2): 321-46.
This paper develops a model of seasonal fluctuations in fecundability, conceptions, and births. We begin with a model of individual fecundability that combines behavioral and biological components, with particular attention to the roles of coital frequen cy, sperm concentration, fetal loss, and contraception. The individual-level model is then expanded into a model of seasonal fluctuations in births at the population level, which accounts explicitly for seasonal fluctuations in the size of the susceptibl e population. We illustrate the use of the model by analyzing proposed explanations of birth seasonality that rely on extreme summer heat.