A Bayesian model of later life mortality trends and implications for longevity

Olshansky S.J., Willcox B.J., Demetrius L., Beltrán-Sánchez H.

Over the course of the twentieth century, human life expectancy at birth rose in high-income nations by approximately 30 years, largely driven by advances in public health and medicine. Mortality reduction was observed initially at an early age and continued into middle and older ages. However, it was unclear whether this phenomenon and the resulting accelerated rise in life expectancy would continue into the twenty-first century. Here using demographic survivorship metrics from national vital statistics in the eight countries with the longest-lived populations (Australia, France, Italy, Japan, South Korea, Spain, Sweden and Switzerland) and in Hong Kong and the United States from 1990 to 2019, we explored recent trends in death rates and life expectancy. We found that, since 1990, improvements overall in life expectancy have decelerated. Our analysis also revealed that resistance to improvements in life expectancy increased while lifespan inequality declined and mortality compression occurred. Our analysis suggests that survival to age 100 years is unlikely to exceed 15% for females and 5% for males, altogether suggesting that, unless the processes of biological aging can be markedly slowed, radical human life extension is implausible in this century. In the twentieth century, human life expectancy rose dramatically. Based on the past three decades of observed mortality in the eight countries with the longest-lived populations and in Hong Kong and the United States, Olshansky et al. propose that, without medical breakthroughs that slow aging, radical lifespan extension is implausible in this century.

Aksan A., Chakraborty S.

We document the evolution of life expectancies around the world during 1960-2015 using graphical analysis, statistical decomposition of survival gains by age-groups and by measuring the contribution of each age-group to changes in the global and regional distributions of life expectancy at birth. We emphasize three findings. First, enormous gains in early-life survival have led to unconditional convergence in life expectancy at birth across countries while late-life longevity has diverged. Gains have been higher for females than males. Secondly, global and regional survival gains among the elderly, though smaller than among the young, have strongly influenced changes in country rankings of life expectancy at birth with the exception of sub-Saharan Africa. Country rankings for late-life survival have changed relatively more than for younger ages. Third, the divergence in survival gains among the elderly is related to disparities in healthcare access, driven in part by within- and between-country income inequality. While providing fresh insight into the uneven pace of health changes during the past half century, these results also highlight how policy can address the socio-economic and demographic consequences of aging.

Wong J.E., Fried L.P., Dzau V.J.

In 2019, the United States of America National Academy of Medicine (NAM) charged an international, independent, and multidisciplinary commission with the development of a consensus report: “The Global Roadmap for Healthy Longevity,” to assess the challenges presented by population ageing and make evidence-based recommendations for how these challenges can be translated into opportunities for societies globally. In this paper, we highlight these recommendations, and show how they can generate a virtuous cycle, starting with a whole-of-society investment in key enablers, especially social infrastructure, the physical environment, health systems, work and volunteerism opportunities, and lifelong learning and retraining, with social cohesion, equity, and a strong social compact at the centre, resulting in populations having good health throughout their life course, triggering a longevity dividend from untapped human, social and economic capital as life spans increase.

Levantesi S., Nigri A., Piscopo G., Spelta A.

Healthy life expectancy (HLE) is an indicator that measures the number of years individuals at a given age are expected to live free of disease or disability. HLE forecasting is essential for planning the provision of health care to elderly populations and appropriately pricing Long Term Care insurance products. In this paper, we propose a methodology that simultaneously forecasts HLE for groups of countries and allows for investigating similarities in their HLE patterns. We firstly apply a functional data clustering to the multivariate time series of HLE at birth of different countries for the years 1990–2019 provided by the Global Burden of Disease Study. Three clusters are identified for both genders. Then, we carry out the HLE simultaneous forecasting of the populations within each cluster by a multivariate random walk with drift. Numerical results and the statistical significance of the parameters of the identified multivariate processes are shown. Demographic evidences on the different evolution of HLE between countries are commented.

Tang S., Li J., Tickle L.

Abstract One complication in mortality modelling is capturing the impact of risk factors that contribute to mortality differentials between different populations. Evidence has suggested that mortality differentials tend to diminish over age. Classical methods such as the Gompertz law attempt to capture mortality patterns over age using intercept and slope parameters, possibly causing an unjustified mortality crossover at advanced ages when applied independently to different populations. In recent research, Richards (Scandinavian Actuarial Journal2020(2), 110–127) proposed a Hermite spline (HS) model that describes the age pattern of mortality differentials using one parameter and circumvents an unreasonable crossover by default. The original HS model was applied to pension data at individual level in the age dimension only. This paper extends the method to model population mortality in both age and period dimensions. Our results indicate that in addition to possessing desirable fitting properties, the HS approach can produce accurate mortality forecasts, compared with the Gompertz and P-splines models.

Schöley J., Aburto J.M., Kashnitsky I., Kniffka M.S., Zhang L., Jaadla H., Dowd J.B., Kashyap R.

The COVID-19 pandemic triggered an unprecedented rise in mortality that translated into life expectancy losses around the world, with only a few exceptions. We estimate life expectancy changes in 29 countries since 2020 (including most of Europe, the United States and Chile), attribute them to mortality changes by age group and compare them with historic life expectancy shocks. Our results show divergence in mortality impacts of the pandemic in 2021. While countries in western Europe experienced bounce backs from life expectancy losses of 2020, eastern Europe and the United States witnessed sustained and substantial life expectancy deficits. Life expectancy deficits during fall/winter 2021 among people ages 60+ and <60 were negatively correlated with measures of vaccination uptake across countries (r60+ = −0.86; two-tailed P < 0.001; 95% confidence interval, −0.94 to −0.69; r<60 = −0.74; two-tailed P < 0.001; 95% confidence interval, −0.88 to −0.46). In contrast to 2020, the age profile of excess mortality in 2021 was younger, with those in under-80 age groups contributing more to life expectancy losses. However, even in 2021, registered COVID-19 deaths continued to account for most life expectancy losses. In 2021, life expectancies returned to pre-pandemic levels in parts of western Europe but further worsened in eastern Europe, the United States and Chile. Life expectancy deficits were negatively correlated with vaccine uptake in later 2021.

Aliverti E., Mazzuco S., Scarpa B.

Nigri A., Barbi E., Levantesi S.

This study investigates the long-term dynamics of longevity by taking into account the specific contribution of each country, and how this has changed over time, thus highlighting different timing and speeds of the evolution of life expectancy among the low-lowest mortality countries. Leveraging on quantile regression, we analyze the specific position of countries that have recorded the maximum (BPLE) and second-best life expectancy value at least once in the period 1960-2014, both at ages 0 and 65. Moving in this direction, the purpose of our contribution is to provide new perspectives on the untracked behavior that may be overshadowed by the maximum longevity levels. Our results provide a comprehensive picture of the different phases and transitions experienced by developed countries in the evolution of life expectancy that has led to a continuous increase in the BPLE. This study is a prominent practice in detecting untracked behaviors, providing imminent onsets on the maximum and sub-maximum values, thus contributing to new clues for future longevity.

Morwinsky S., Nitsche N., Acosta E.

Scott A.J.

As the demographic transition enters a new stage of a longevity transition, focus needs to extend beyond an ageing society towards a longevity society. An ageing society focuses on changes in the age structure of the population, whereas a longevity society seeks to exploit the advantages of longer lives through changes in how we age. Achieving a longevity society requires substantial changes in the life course and social norms, and involves an epidemiological transition towards a focus on delaying the negative effects of ageing. The broad changes required to achieve healthy longevity include an increased focus on healthy life expectancy, a shift from intervention towards preventive health, a major public health agenda to avoid increases in health inequality, the establishment of longevity councils to ensure coordinated policy across government departments, and intergenerational assessment of policies, to ensure that in adapting to longer lives, policies are not skewed towards older people. A longevity society represents a new stage for humanity and requires deep-seated notions about age and ageing to be challenged if society is to make the best use of the additional time that longevity brings.

Leggat-Barr K., Uchikoshi F., Goldman N.

Hardy O.J., Dubourg D., Bourguignon M., Dellicour S., Eggerickx T., Gilbert M., Sanderson J., Scohy A., Vandael E., Decroly J.

Aburto J.M., Schöley J., Kashnitsky I., Zhang L., Rahal C., Missov T.I., Mills M.C., Dowd J.B., Kashyap R.

Abstract Background Variations in the age patterns and magnitudes of excess deaths, as well as differences in population sizes and age structures, make cross-national comparisons of the cumulative mortality impacts of the COVID-19 pandemic challenging. Life expectancy is a widely used indicator that provides a clear and cross-nationally comparable picture of the population-level impacts of the pandemic on mortality. Methods Life tables by sex were calculated for 29 countries, including most European countries, Chile and the USA, for 2015–2020. Life expectancy at birth and at age 60 years for 2020 were contextualized against recent trends between 2015 and 2019. Using decomposition techniques, we examined which specific age groups contributed to reductions in life expectancy in 2020 and to what extent reductions were attributable to official COVID-19 deaths. Results Life expectancy at birth declined from 2019 to 2020 in 27 out of 29 countries. Males in the USA and Lithuania experienced the largest losses in life expectancy at birth during 2020 (2.2 and 1.7 years, respectively), but reductions of more than an entire year were documented in 11 countries for males and 8 among females. Reductions were mostly attributable to increased mortality above age 60 years and to official COVID-19 deaths. Conclusions The COVID-19 pandemic triggered significant mortality increases in 2020 of a magnitude not witnessed since World War II in Western Europe or the breakup of the Soviet Union in Eastern Europe. Females from 15 countries and males from 10 ended up with lower life expectancy at birth in 2020 than in 2015.

Scott A.J., Ellison M., Sinclair D.A.

Developments in life expectancy and the growing emphasis on biological and ‘healthy’ aging raise a number of important questions for health scientists and economists alike. Is it preferable to make lives healthier by compressing morbidity, or longer by extending life? What are the gains from targeting aging itself compared to efforts to eradicate specific diseases? Here we analyze existing data to evaluate the economic value of increases in life expectancy, improvements in health and treatments that target aging. We show that a compression of morbidity that improves health is more valuable than further increases in life expectancy, and that targeting aging offers potentially larger economic gains than eradicating individual diseases. We show that a slowdown in aging that increases life expectancy by 1 year is worth US$38 trillion, and by 10 years, US$367 trillion. Ultimately, the more progress that is made in improving how we age, the greater the value of further improvements. An economic analysis suggests that targeting aging offers potentially larger economic gains than eradicating individual diseases. Slowing aging to increase life expectancy by 1 year is worth US$38 trillion, and by 10 years, US$367 trillion.

Bravo J.M., Ayuso M., Holzmann R., Palmer E.

Understanding the systematic relationship between period and cohort life expectancy and how the relationship evolves over time are critical issues in formulating the design of retirement income products, evaluating the actuarial balance of pension schemes, and more generally for all analyses where demographic projections are involved. In this study, estimates of the life expectancy gap at all ages are performed using data for 1960–2018 from the Human Mortality Database and projections are generated through 2050 for the 42 national populations, disaggregated by sex. Contrary to previous research that often uses a single deemed to be «best» model to forecast mortality rates, we use a novel adaptive Bayesian Model Ensemble of heterogeneous parametric generalized age-period-cohort stochastic mortality models, principal component methods, and smoothing approaches. The procedure involves both the selection of the model confidence set and the determination of optimal weights. Model-averaged Bayesian credible prediction intervals are derived accounting for both the uncertainty arising from model error and parameter uncertainty. With intergenerational actuarial fairness and neutrality as the guiding principles the study then explores potential policy interventions to address the consequences of the life expectancy gap - spanning over adjustments in the accumulation, benefit determination, and payout stages. Comprehensive numerical results are provided for two policy options: (i) introducing a sustainability factor; and (ii) conditional pension indexation. The results show that: (i) the life expectancy gap is positive and significant for almost all countries and years studied, (ii) it will continue to increase, (iii) the magnitude of the subsidy rates between generations can be sizeable demanding important initial pension benefit reduction and/or a gradual diminution in the annual indexation rate of pensions to correct them.