Exploring Stable Population Concepts from the Perspective of Cohort Change Ratios

Cohort Change Ratios (CCRs) have a long history of use in demography, but they appear, however, to have been overlooked in regard to stable population theory. In this paper, we explore the use of CCRs as a tool for examining the idea of a stable population. Our exploration utilizes four case studies that represent current populations that have very difference dynamics. In comparing the approach using CCRs to the traditional approach, we note benefits and drawbacks. Benefits of the CCR approach include the ability to easily deal with both sexes, all of the components of change, including migration, and, importantly, an indication of how much time would be needed under a constant set of CCRs for a given population to become stable. To this end, we have developed an Index of Stability and demonstrate its use in the context of regression modeling.