Volume 9 - Article 6 | Pages 111–118  

A diminishing population whose every cohort more than replaces itself

By Robert Schoen, Stefan H. Jonsson

Abstract

We observe that a dynamic population model can have period fertility that is always below replacement and cohort fertility that is always above replacement. We ask whether such a paradoxical population will get larger or smaller, and show that it must become smaller. Cohort replacement does not imply population replacement, and emphasizing fertility timing and cohort fertility ignores the issue of relative cohort size. The resolution of this apparent paradox reinforces the importance of the level of period fertility in demographic analysis.

Author's Affiliation

Other articles by the same author/authors in Demographic Research

Estimating multistate transition rates from population distributions
Volume 9 - Article 1

A dynamic birth-death model via Intrinsic Linkage
Volume 28 - Article 35

Age-specific growth, reproductive values, and intrinsic r
Volume 24 - Article 33

The metastable birth trajectory
Volume 21 - Article 25

A behaviorally-based approach to measuring inequality
Volume 19 - Article 49

Changing mortality and average cohort life expectancy
Volume 13 - Article 5

Age-specific contributions to changes in the period and cohort life expectancy
Volume 13 - Article 3

Intrinsically dynamic population models
Volume 12 - Article 3

On the Impact of Spatial Momentum
Volume 6 - Article 3

Toward a General Model for Populations with Changing Rates
Volume 4 - Article 6

Most recent similar articles in Demographic Research

Advanced or postponed motherhood? Migrants’ and natives’ gap between ideal and actual age at first birth in Spain
Volume 49 - Article 22    | Keywords: actual age at first birth, age at arrival, fertility, ideal age at first birth, international migration, motherhood, Spain

Describing the Dutch Social Networks and Fertility Study and how to process it
Volume 49 - Article 19    | Keywords: fertility, Netherlands, personal networks, social influence

Partial fertility recuperation in Spain two years after the onset of the COVID-19 pandemic
Volume 49 - Article 17    | Keywords: COVID-19, fertility, recuperation, Spain

The quality of fertility data in the web-based Generations and Gender Survey
Volume 49 - Article 3    | Keywords: accuracy, data quality, fertility, Generations and Gender Survey (GGS)

Subnational variations in births and marriages during the COVID-19 pandemic in South Korea
Volume 48 - Article 30    | Keywords: COVID-19, fertility, Korea, marriage