Stable populations revisited

Anders Ahlbom, Karolinska Institutet
Sven Drefahl, Stockholm University
Vladimir Canudas-Romo, Johns Hopkins University
Karin Modig, Karolinska Institutet

We collected data on the age structure, mortality, and fertility of the Swedish population from Statistics Sweden and the Human Mortality Database to investigate some aspects of the Swedish population at 1900 and onwards using stable population models. Using the fertility and mortality rates for the year 1900 we found a very good agreement between the actual population age structure and the corresponding stable population age structure for both sexes combined. This was not the case for the year 2000. In a second step we investigated the relative impact of a decreased fertility and a decreased mortality on the age distributions. The conclusion from this exercise is that the big changes to the age distribution that have taken place during the previous century largely are the result of lowered fertility, not of increased life expectancy. A discussion of the implications of the results will be ready for the EPC meeting.