Volume 6 - Article 3 | Pages 49-66

On the Impact of Spatial Momentum


Date received:	03 Sep 2001
Date published:	29 Jan 2002
Word count:	3773
Keywords:	population growth, population momentum, spatial momentum, urbanization
DOI:	10.4054/DemRes.2002.6.3

Abstract

Momentum, the population growth that occurs after a fall in fertility to replacement level, has long been appreciated as a factor in the future population growth of many countries. This paper argues that another aspect of growing populations - their high proportion rural - is also a source of significant growth, and refers to the additional growth attributable to geographical redistribution as spatial momentum.
Using simplifying assumptions, a model for analyzing spatial momentum is developed based on population composition, rates of growth, and levels of interregional migration. Calculations are then done using (i) hypothetical populations exhibiting a range of plausible demographic behavior, and (ii) the population of Mexico, 1970. The results show that spatial momentum can have a substantial impact on ultimate population size under commonly encountered circumstances.