Department of Population Health, London School of Hygiene and Tropical Medicine, United Kingdom; Centre for Actuarial Research, University of Cape Town, South Africa
TimÆus, I.M., Department of Population Health, London School of Hygiene and Tropical Medicine, United Kingdom; Moultrie, T.A., Centre for Actuarial Research, University of Cape Town, South Africa
This paper investigates the impact on birth intervals of three distinct birth control strategies: stopping childbearing, spacing births and the postponement of further childbearing for reasons unrelated to women's family-building histories. A macro-simulation model of the family-building process is described that incorporates heterogeneity in fecundability. This model is used to demonstrate that the postponement of further childbearing has a distinctive impact on schedules of duration-specific fertility rates that differs from that of both family-size limitation and birth spacing. In particular, the simulation results, supplemented by an analytical exposition, show that reductions in fertility due to spacing are a function of interval duration and its log, while reductions due to postponement are a function of interval duration and its square. This provides a way to test statistically for the presence of, and distinguish between, differential postponement and spacing in regression analyses of birth history data. © 2012 Cambridge University Press.
age; contraception; family planning; family size; female; fertility; human; parity; pregnancy; statistical model; statistics and numerical data; article; contraception; family planning; statistics; Age Factors; Birth Intervals; Contraception; Family Characteristics; Female; Fertility; Humans; Models, Statistical; Parity; Pregnancy; Age Factors; Birth Intervals; Contraception; Family Characteristics; Female; Fertility; Humans; Models, Statistical; Parity; Pregnancy