Decomposing and Recomposing the Population Pyramid by Remaining Years of Life

Timothy L. M. Riffe, University of California, Berkeley
Jeroen J. A. Spijker, University of Edinburgh
John MacInnes, University of Edinburgh

We apply a simple decomposition method to age-classified population counts in order to derive a probabilistic distribution of remaining lifetimes within age-classes. This decomposition method allows us to invert the population pyramid so as to be classified by remaining years of life. This paper is a graphical exploration of the kinds of information that such an image can yield. We think that this age-specific remaining-years decomposition should become part of the basic demographer's toolkit for many reasons. We also suggest a rich visualization for consideration as a basic product for consumers of demographic information.