A growing number of studies indicate a widening of socioeconomic inequalities in mortality over the past decades. It has therefore become crucially important to understand the impact of heterogeneity and its evolution on the future mortality of heterogeneous populations. In particular, recent developments in multi-population mortality have raised a number of questions, among which is the issue of evaluating cause-of-death reduction targets set by national and international institutions in the presence of heterogeneity. The aim of this paper is to show how the study of the population data and the population dynamics framework contribute to addressing these issues, by providing a new viewpoint on the evolution of aggregate mortality indicators in the presence of heterogeneity. Our findings rely on two unique datasets on the English population and cause-specific number of deaths by socioeconomic circumstances, over the period 1981-2015. The analysis of the data first highlights the complexity of recent demographic developments, characterized by significant composition changes in the population, with considerable variations according to the age class or cohort, along with a widening of socioeconomic inequalities. We then introduce a dynamic framework for studying the impact of composition changes on the mortality of the global population. In particular, we are interested in quantifying the impacts of cause-of-death mortality reduction in comparison with changes of composition in a heterogeneous population. We show how a cause of death reduction could be compensated for in the presence of heterogeneity, which could lead to misinterpretations when assessing public policies impacts and/or for the forecasting of future trends.

Background: The discovery of biomarkers of ageing has led to the development of predictors of impending natural death and has paved the way for personalised estimation of the risk of death in the general population. This study intends to identify the ethical resources available to approach the idea of a long-lasting dying process and consider the perspective of death prediction. The reflection on human mortality is necessary but not sufficient to face this issue. Knowledge about death anticipation in clinical contexts allows for a better understanding of it. Still, the very notion of prediction and its implications must be clarified. This study outlines in a prospective way issues that call for further investigation in the various fields concerned: ethical, psychological, medical and social. Methods: The study is based on an interdisciplinary approach, a combination of philosophy, clinical psychology, medicine, demography, biology and actuarial science. Results: The present study proposes an understanding of death prediction based on its distinction with the relationship to human mortality and death anticipation, and on the analogy with the implications of genetic testing performed in pre-symptomatic stages of a disease. It leads to the identification of a multi-layered issue, including the individual and personal relationship to death prediction, the potential medical uses of biomarkers of ageing, the social and economic implications of the latter, especially in regard to the way longevity risk is perceived. Conclusions: The present study work strives to propose a first sketch of what the implications of death prediction as such could be-from an individual, medical and social point of view. Both with anti-ageing medicine and the transhumanist quest for immortality, research on biomarkers of ageing brings back to the forefront crucial ethical matters: should we, as human beings, keep ignoring certain things, primarily the moment of our death, be it an estimation of it? If such knowledge was available, who should be informed about it and how such information should be given? Is it a knowledge that could be socially shared?

Background: The discovery of biomarkers of ageing has led to the development of predictors of impending natural death and has paved the way for personalised estimation of the risk of death in the general population. This study intends to identify the ethical resources available to approach the idea of death as a process and consider the perspective of death prediction. The reflection on human mortality is necessary but not sufficient to face this issue. Knowledge about death anticipation in clinical contexts allows for a better understanding of it. Still, the very notion of prediction and its implications must be clarified. This study outlines in a prospective way issues that call for further investigation in the various fields concerned: ethical, psychological, medical and social.Methods: The study is based on an interdisciplinary approach, a combination of philosophy, clinical psychology, medicine, demography, biology and actuarial science.Results: The present study proposes an understanding of death prediction based on its distinction with the relationship to human mortality and death anticipation, and on the analogy with the implications of genetic testing performed in pre-symptomatic stages of a disease. It leads to the identification of a multi-layered issue, including the individual and personal relationship to death prediction, the potential medical uses of biomarkers of ageing, the social and economic implications of the latter, especially in regard of the way the longevity risk is perceived.Conclusions: The present study work strives to propose a first sketch of what the implications of death prediction as such could be -from an individual, medical and social point of view. Both with antiageing medicine and the transhumanist quest for immortality, research on biomarkers of ageing brings back to the forefront crucial ethical matters: should we, as human beings, keep ignoring certain things, primarily the moment of our death, be it an estimation of it? If such knowledge was available, who should be informed about it and how such information should be given? Is it a knowledge that could be socially shared? BackgroundDeath prediction is not a new idea, neither at a population level nor at an individual one. Since the late 17th century, demographers have routinely estimated and analysed multiple population-level

This paper deals with the stochastic modeling of a class of heterogeneous population dynamics in a random environment. These Birth-Death-Swap populations generalize Markov multi-type Birth-Death processes, by considering swap events (moves between subgroups) in addition to demographic events, and allowing event intensities to be random functional of the population. The complexity of the problem is significantly reduced by modeling the jumps measure of the population, described by a multivariate counting process. In the spirit of Massoulié (1998), this process is defined as the solution of a stochastic differential system with random coefficients, driven by a multivariate Poisson random measure. The solution is obtained under weaker assumptions than usual, by thinning of a dominating point process driven by the same Poisson measure.This key construction rely on a general comparison result of independent interest. The second part is dedicated to averaging results when swap events are more frequent than demographic events. An important ingredient is the stable convergence which extends naturally the convergence in distribution in the presence of a random environment. The pathwise construction by domination yields straightforward tightness results, in particular for the population process which is considered as a simple variable on Ω × R + . At the limit, the demographic intensity functionals are averaged against random kernels depending on swap events. Finally, we show under a natural assumption the convergence of the aggregated population to a "true" Birth-Death process in random environment with density-dependence.