Revisiting mid-twentieth-century fertility shifts from a global perspective.

In the developed world, the historic process of fertility decline was interrupted by an unexpected period of increasing fertility called the baby boom. Recent studies suggest that a similar trend change in fertility may have occurred in many less developed nations at approximately the same time. Using cohort fertility data for 26 less developed countries from around the world taken from the Integrated Public Use Microdata Series, International (IPUMS-I), this paper aims to ascertain the extent to which these trend changes occurred in a large sample of countries around the world. It offers convincing proof of the existence of an upward shift in fertility among cohorts born during the 1930s, which was common to many countries in the less developed world. Despite many similarities with the baby boom, there are also differences stemming, mostly, from its timing with respect to the demographic transition.