Natalia S. Gavrilova , University of Chicago
Leonid A. Gavrilov, University of Chicago
What is happening with the old age mortality trajectories over time and how do the trends vary by region? This study attempts to answer these questions by analyzing historical evolution of the old-age mortality in three countries: United States, Canada and the United Kingdom. Earlier studies demonstrated that exponential growth of mortality with age (the Gompertz law) slows down after age 80 years resulting in mortality deceleration. However more recent studies of the U.S. birth cohorts failed to observe mortality deceleration up to very old ages of 105 years. We compared performance (goodness-of-fit) of two competing mortality models - the Gompertz model and the "mortality deceleration" Kannisto model at ages 80-105 years using data for 1880-1899 single-year birth cohorts of men and women in the U.S., Canada and the United Kingdom. The mortality modeling approach suggests a transition from mortality deceleration in earlier birth cohorts to the Gompertzian mortality pattern in later birth cohorts for both men and women. Transition from mortality deceleration to the Gompertz law occurs later in Canada and the United Kingdom compared to the United States. These results are consistent with the hypothesis about mortality deceleration fading away over time due to improvement in the accuracy of age reporting. This leads to more conservative estimates for future human longevity records and the proportion of older people (population aging).
Presented in Session 17. Oldest Old