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

• Robert Schoen - Pennsylvania State University, United States of America EMAIL
• Stefan H. Jonsson - Pennsylvania State University, United States of America EMAIL

Other articles by the same author/authors in Demographic Research

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A dynamic birth-death model via Intrinsic Linkage
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Age-specific growth, reproductive values, and intrinsic r
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The metastable birth trajectory
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A behaviorally-based approach to measuring inequality
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Changing mortality and average cohort life expectancy
Volume 13 - Article 5

Age-specific contributions to changes in the period and cohort life expectancy
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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
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