José Manuel Aburto^a,b^, Francisco Villavicencio^c^, Ugofilippo Basellini^d^, Søren Kjærgaard^a^, James W. Vaupel^a,b,e^
Author affiliations:
a Interdisciplinary Centre on Population Dynamics (CPop), University of Southern Denmark, Odense 5000, Denmark.
b Max Planck Institute for Demographic Research, Rostock 18057, Germany
c Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Balti-more, MD 21205.
d Institut national d’études démographiques (INED), F-75020 Paris, France
e Duke University Population Research Institute, Duke University, Durham, NC 27708.
Any question please send it to jm.aburto01@gmail.com
As people live longer, ages at death are becoming more similar. This dual advance over the last two centuries, a central aim of public health policies, is a major achievement of modern civilization. Some recent exceptions to the joint rise of life expectancy and lifespan equality, however, make it difficult to determine the underly-ing causes of this relationship. Here, we develop a unifying framework to study life expectancy and lifespan equality over time relying on concepts about the pace and shape of aging. We study the dynamic relationship between life expectancy and lifespan equality with reliable data from the Human Mortality Database for 49 countries and regions with emphasis on the long time series of Swedish mortality. Our results demonstrate that both changes in life expectancy and lifespan equality are weighted totals of rates of progress in reducing mortality. This finding holds for three different measures of the variability of lifespans. The weights evolve over time and indicate the ages at which reductions in mortality increase life expectancy and lifespan equali-ty: the more progress at the youngest ages, the tighter the relationship. The link between life expectancy and lifespan equality is especially strong when life expectancy is less than 70 years. In recent decades life expec-tancy and lifespan equality have occasionally moved in opposite directions due to larger improvements in mortality at older ages or a slowdown in declines in midlife mortality. Saving lives at ages below life expec-tancy is the key to increasing both life expectancy and lifespan equality.
