The Shape of a Fertility Transition: An Analysis of Birth Intervals in Eastern Belgium

George Alter, Indiana University
Michel Oris, Université de Genève
Konstantin Tyurin, Indiana University

Henry’s “natural fertility hypothesis,” which asserts that fertility control consisted of “stopping” high parity births without increasing the “spacing” between births, has been central to research on both historical and contemporary fertility transitions. This hypothesis has never been universally accepted, and methods for detecting fertility transitions based only on “stopping” have been increasingly challenged. This paper offers a new perspective illustrated with fertility histories from 19th-century Belgium. We show that “stopping” and “spacing” can both be identified by examining survival curves for birth intervals. We also show that these features of birth intervals are captured by the “cure model,” which allows us to estimate effects of covariates on “stopping” and “spacing” separately. Our results confirm that stopping rather than spacing was the primary control strategy used during the fertility transition in 19th-century Belgium, and couples were abandoning behaviors (e.g. prolonged breastfeeding, abstinence) that lengthened birth intervals in previous generations.