Matt Hauer and Carl Schmertmann (both on Twitter) have just published a new paper that promises to be a game changer in population studies. They devised a method to estimate total fertility rates using inputs as minimal as the age/sex structure of a population. They tested the accuracy of the method using 2400+ fertility schedules and the result is incredibly accurate. Matt has written a thread on Twitter summarizing some of the key aspects of the paper. The code to replicate the paper is here and an ungated preprint of the paper can be downloaded here.
Hauer, M., & Schmertmann, C. (2018). Population pyramids yield accurate estimates of total fertility rates. Demography. https://doi.org/10.1007/s13524-019-00842-x []
Abstract:
The primary fertility index for a population, the total fertility rate (TFR), cannot be calculated for many areas and periods because it requires disaggregation of births by mother’s age. Here we discuss a flexible framework for estimating TFR using inputs as minimal as a population pyramid. We develop five variants, each with increasing complexity and data requirements. We test accuracy across a diverse set of data sources that comprise more than 2,400 fertility schedules with known TFR values, including the Human Fertility Database, Demographic and Health Surveys, U.S. counties, and nonhuman species. We show that even the simplest and least accurate variant has a median error of only 0.09 births per woman over 2,400 fertility schedules, suggesting accurate TFR estimation over a wide range of demographic conditions. We anticipate that this framework will extend fertility analysis to new subpopulations, periods, geographies, and even species. To demonstrate the framework’s utility in new applications, we produce subnational estimates of African fertility levels, reconstruct historical European TFRs for periods up to 150 years before the collection of detailed birth records, and estimate TFR for the United States conditional on race and household income.
Estimated TFR from Population Pyramids. We compare the performance of five variants against observed TFRs using data from the Human Fertility Data, Demographic and Health Surveys, the US Census Bureau, and various non-human species.
