On the momentum of pseudostable populations

Arbeitspapier

In a pathbreaking paper Keyfitz (1971) calculated the demographic momentum, i.e. the amount of further population growth if an immediate reduction of fertility to bare replacement would occur. While he assumes a stable initial population, our research aims to extend it to so-called pseudostable populations where fertility declines at a constant rate while mortality remains fixed. We were able to analytically obtain interesting insights into the momentum of growth of such populations. Comparing theoretical results in a pseudostable setting with the projections according to the component method showed a fit that was un-expectedly remarkably good. A peculiar effect of pseudostability is the monotonous decline of the momentum over time. Starting from a certain fixed level in the remote p ast, the m omentum c onverges to zero for an infinite time horizon. Interestingly enough, there is a time where there is neither a positive nor a negative momentum. To put it numerically, a remarkable asymmetry in the momentum is revealed. While an immediate fertility change may lead to a maximal increase of the population by a factor between 2 and 3, the maximal decrease runs up to 100%.

Object Details

• Language: Englisch

References and Relationships

• Bibliographic citation: Series: Vienna Institute of Demography Working Papers ; No. 01/2023

Classification and Topics

• Classification: Sozialwissenschaften, Soziologie, Anthropologie

Contributors, Places and Time

• Event: Geistige Schöpfung
• (who): Feichtinger, Gustav ; Rau, Roland ; Novak, Andreas J.
• Event: Veröffentlichung
• (who): Austrian Academy of Sciences (ÖAW), Vienna Institute of Demography (VID)
• (where): Vienna
• (when): 2023

Further information

• DOI: doi:10.1553/0x003e187b
• Handle: http://hdl.handle.net/10419/278413
• Last update: 10.03.2025, 11:42 AM CET