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Old age and adult mortality have over the last decades enjoyed a remarkable decline throughout the western world, posing the researcher with new challenges and opening up fresh horizons in life expectancy trends. The recent drop in mortality may be largely traced to the unexpected decline in cardiovascular diseases and certain cancers. Thus it could be hoped that in the future these trends would continue and extend to include other causes where, for the moment, little change has occurred. Such a hypothesis is all the more realistic in view of the fact that recent changes are linked, not just to advances in more efficacious medical treatment, but also to a growing awareness on the part of the general public regarding questions of health and the crucial role played by life style and behaviour. These include improved dietary habits, for example, a better attitude to risk factors, particularly to smoking, alcohol abuse, dangerous driving, etc. This awareness, which prevails among more recent, well-informed and better educated cohorts, not only produces immediate results, but maybe even more so in the future, should this spare coming generations the accumulation of risks which were and continue to be the burden particularly of older cohorts.

The persistence of mortality decline at all ages, and particularly at older ages, means that an increasing number of individuals are becoming centenarians and semi-super centenarians. Our hypothesis is that the gender differences in mortality level in old ages had an impact on the number of men and women reaching 100 years and so on the gender gap. Work-related international migration was also an important characteristic of Italian cohorts born in the last decades of the Nineteenth century, and in the first decades of the Twentieth, as these migrations affected more men than women. Referring to the Istat (Italian National Institute of Statistics) mortality data (Cause of Death Survey and Deaths of Resident Population survey) and the Semi super and Super centenarians Surve -SSC, that has been realized by Istat since 2009, the aim of this paper is to present the development of the gender gap for the cohorts born between 1870 and 1912 beyond 100 and 105 years old. We have confirmed our hypothesis, explaining the characteristics of this development on the basis of estimates of the role played by the different migratory histories of the two genders and, above all, by the differences in the male and female survival trajectories of the cohorts in the study.

Although the increase in the number of centenarians is well documented today in countries with advanced demographic data, the same is not true for those aged 105 years and over. The first aim of this paper was to analyze the demographic characteristics of the 4,626 validated semisuper and 102 supercentenarians for the cohorts born between 1896 and 1910, referring to Italian Semi-Supercentenarians Survey. Then, starting from this data and from the survival histories in old ages-reconstructed by Vincent's Extinct - Cohort Method-for the cohorts born between 1870 and 1904, the most important aim was to analyze longevity history and the trend of gender gap of the Italian oldest cohorts beyond 100 years old. The Italian centenarians and semisupercentenarians increase from the first to the last cohort is due to the survival rise in old ages and the increase in the gender gap at extreme ages depends on the higher survival of women than men after 60 years old. Around 110-112 for both genders (for women in particular) a kind of resistance to further progress seems to appear in our analysis as in more recent studies on supercentenarians.

This chapter provides an overview of past and expected future trends in life expectancy in populations with low levels of mortality. High and low mortality populations were separated on the basis of the level of child mortality in the year 2010 according to the revised estimates of the United Nations Inter-agency Group for Child Mortality Estimation (2011), with the threshold being 40 deaths per 1,000 children below the age of 5 years. The low mortality population is comprised of 132 countries including Europe, North America, most of Oceania and Latin America, large parts of Asia (excluding the high mortality area in Central and Southern Asia), and Northern Africa. The populations of these countries are already engaged in an advanced phase of the demographic and ‘epidemiologic transition’. Because they previously experienced strong decreases in infant mortality, the future mortality trends are driven mainly by mortality in adult ages, primarily the old and oldest-old. Although the data sources on which the existing estimates of life expectancy for these populations are based vary considerably (owing to differences in the death registration systems and the estimation techniques, see, e.g., Luy, 2010), we have relatively good knowledge of past and current mortality levels and trends and their causes. Despite the similar general trends, today’s low mortality countries are very heterogeneous in various aspects, including medical standards, access to health care, and behavioural risk factors, such as smoking prevalence. These diversities are strongly related to the populations’ stages of economic development and contribute to a broad variance of life expectancy levels. Among men, life expectancy at birth for the years 2005–10 ranges between 60.2 in Kazakhstan and 79.5 in Iceland. Among women, the range is between 67.8 in the Solomon Islands and 86.1 in Japan. To demonstrate this relationship between economic development and life expectancy we classified countries according to their current per capita income as an indicator of the economic development level of the populations. We used the World Bank classification, which groups countries into high income (≥$12,276 annually), upper middle income ($3,976–$12,275), lower middle income ($1,006–$3,975), and low income (≤$1,005).

The 2013 issue of the Vienna Yearbook of Population Research presents a series of studies on the determinants of unusual and differential longevity. In the Western world, life expectancy has increased continuously during the last 150 years, leading some experts to speak of ‘broken limits to life expectancy’ (Oeppen and Vaupel 2002). We are witnessing a real revolution, made possible by major reductions in mortality among elderly persons. Today, more than half the population in the Western world survive until their 80th birthday. The number of people between 90 and 100 years is gradually increasing and the age at death is continuously pushed forward to old and oldest-old ages (Wilmoth et al. 2000). Moreover, the number of those dying after age 100 is growing at a higher rate of increase than that for preceding age groups (Caselli et al. 2006a; Robine et al. 2006a, 2006b). The unexpected deceleration of the increase in the force of mortality among the oldest-old has called into question the well-known Gompertz’s Law (1825) of human longevity, encouraging a wide-ranging debate on the reasons for the extension of the human lifespan (Finch and Pike 1996). Biologists and geneticists who study the mechanisms entailed and try to establish at what stage a person is old developed numerous theories on ageing. According to Medvedev (1990), these can be grouped in four main categories: programmed genetic ageing, age-associated changes, primary damage and evolutionary theories. Some of these theories focus on ‘how we age’, others on ‘why we age’ (Williams 1957; Kirkwood 1990; Kirkwood and Rose 1991; Finch and Kirkwood 2000). In the new millennium the number of centenarians has increased to such an extent as to capture the interest of academics from various disciplines to search for the causes of longevity. The first data on the possible determinants of extreme longevity emerged from two major hypotheses, the first regarding a general conceptualisation of the possible biological determinants of the ageing process, and the second originating from studies on the immunological status of centenarians (Capri et al. 2008).The

The aims of this study are to analyse the two-way association between women fertility and longevity, and parental transmission of longevity. The wealth of information gathered in the AKeA2—demographic survey on Sardinian centenarians—have been used by applying Logistic Regression Models. For the association between longevity and fertility, we find evidence that *long livers benefit from factors related to the timing of fertility (in particular the age at birth of the last child) that the literature suggests may foster longevity. Regarding the association with parental transmission, it seems to have significant effects for women but not for men. We always found that a higher birth order decreases the probability of becoming a centenarian. There is a negative effect of a higher father age at birth on the longevity of female offspring. The latter suggests that long-lived women seem to have been favoured both by their own late fertility and young paternal age at the moment of their own procreation.

It is well known that efficacy of immune functions declines with age. It results in an increase of severity and duration of respiratory infections and also in dramatic growth of risk of death due to these diseases after age 65. The goal of this work is to describe and investigate the mechanism underlying the age pattern of the mortality rate caused by infectious diseases and to determine the cause-specific hazard rate as a function of immune system characteristics. For these purposes we develop a three-compartment model explaining observed risk-of-death. The model incorporates up-to-date knowledge about cellular mechanisms of aging, disease dynamics, population heterogeneity in resistance to infections, and intrinsic aging rate. The results of modeling show that the age-trajectory of mortality caused by respiratory infections may be explained by the value of antigenic load, frequency of infections and the rate of aging of the stem cell population (i.e. the population of T-lymphocyte progenitor cells). The deceleration of infection-induced mortality at advanced age can be explained by selection of individuals with a slower rate of stem cell aging. Parameter estimates derived from fitting mortality data indicate that infection burden was monotonically decreasing during the twentieth century, and changes in total antigenic load were gender-specific: it experienced periodic fluctuations in males and increased approximately two-fold in females.

Population ageing involves every aspect of the individual, family and collective life, including the perception and the ‘‘value’’ of the elderly (which is inevitably devalued as a result of their number and the speed of changes in production and technology which easily makes them ‘‘obsolete’’). The current demographic aging is certainly unprecedented in the history of humanity. It is a process that, sooner or later, will spread throughout the world. It involves all social classes and acts on all sub-populations (the school population, the labor force, the old and oldest-old populations). Ageing modifies family structures and every dimensions of human life. For Europe it is a rapid, irreversible process as individuals are living longer and longer, and there are fewer and fewer children (a low number of children per woman and fewer women in reproductive ages). Demographic aging in Europe is accompanied by a slow population decrease, which is counter-acted by a still high number of young people in poor countries and a high growth rate among these populations. These contrasts may cause problems at the global level that may even be difficult to control. The many problems that aging brings are, then, of various kinds, and involve many aspects of public and private life. The eighteen chapters in the volume Aging in European Societies. Healthy Aging in Europe present many of these aspects. An extensive introduction is followed by individual chapters that address specific issues. Chapter 2 on Challenging Statutory Pensions Reforms in an Aging Europe: Adequacy Versus Sustainability, gives a broad description of the stages of pensions reform in Europe, also pointing out some important differences between countries. Unfortunately, the authors do not give many clues on why these differences exist

In this article we discuss relevant data on aging, longevity, and gender with particular focus on inflammation gene polymorphisms which could affect an individual's chance to reach the extreme limit of human life. The present review is not an extensive revision of the literature, but rather an expert opinion based on selected data from the authors' laboratories. In 2000-2005 in the more developed regions, the life expectancy at birth is 71.9 years for men (78.3 in Japan) and 79.3 years for women (86.3 in Japan). Indeed, gender accounts for important differences in the prevalence of a variety of age-related diseases. Considering people of far-advanced age, demographic data document a clear-cut prevalence of females compared to males, suggesting that sex-specific mortality rates follow different trajectories during aging. In Italy this female/male ratio is relatively lower (about 5/1; F/M ratios are usually 5-6:1 in other developed countries), but significant differences have been observed between Italian regions in the distribution of centenarians by gender - from two women per man in the South to more than eight in certain regions in the North. Thus, a complex interaction of environmental, historical, and genetic factors, differently characterizing the various parts of Italy, likely plays an important role in determining the gender-specific probability of achieving longevity. This can be due to gender-specific cultural and anthropological characteristics of Italian society in the last 100 years. Age-related immunoinflammatory factors increase during proinflammatory status, and the frequency of pro/antiinflammatory gene variants also show gender differences. There is some suggestion that people genetically predisposed to weak inflammatory activity may be at reduced chance of developing coronary heart disease (CHD) and, therefore, may achieve longer lifespan if they avoid serious life-threatening infectious disease thoroughout life. Thus, the pathogen burden, by interacting with host genotype, could determine the type and intensity of the immune-inflammatory response responsible for both proinflammatory status and CHD. These findings point to a strong relationship between the genetics of inflammation, successful aging, and the control of cardiovascular disease, but seem to suggest that the evidence for men is much stronger. The importance of these studies lies in the fact that half of the population (males) lives approximately 10% shorter lives than the other half (females). Understanding the different strategies that men and women seem to follow to achieve longevity may help us to comprehend better the basic phenomenon of aging and allow us to search for safe ways to increase male lifespan.

This paper aims to discuss the validation and family determinants affecting the longevity of Sardinian centenarians, using a genealogical approach. This preliminary study presents the first results of a genealogical tree reconstruction of selected centenarians aged 105 and over, from certain areas. These are mostly situated in the province of Nuoro, an area with the highest rate of centenarians and where the female-to-male sex ratio tends to be male-biased. An accurate centenarian age validation was performed that required a meticulous examination of numerous civil status records and parish registers. An important finding was that longevity occurs among the ascendants of a particular branch of the family. The data used are still provisional but, should it apply to other validated cases, it would provide empirical evidence of a genetic component in longevity. A more thorough examination of the data available may yield deeper insights into the role played by endogamy and consanguinity.

A study of centenarians in Sardinia detected the existence of an area where the number of centenarians is higher than elsewhere, in particularly for men. There is a widespread opinion that the existence of a greater or a lesser number of centenarians largely depends on mortality features between 80 and 100 years. This study aims to cast light on our knowledge of elderly mortality differentials, total and by cause of death, in Sardinia, and attempts to verify this hypothesis. To do so, an analysis is conducted of age and sex mortality trends over time at province and municipality level. Results fully confirm the underlying hypothesis.

Significant differentials have been observed between Italian regions in the distribution of centenarians by sex, from two women per man in the south to over eight in certain regions in the north. In order to explain these differentials we studied the evolution of the femininity ratio (FR), using a longitudinal approach to follow the ageing process in two cohorts, and making use of nearly all the statistical data available since the time of the Unification of Italy in 1870. Significant differentials in the FR observed at the age of 100 are mainly due to mortality differentials among men over the age of 60. The high mortality of men in the north and their low mortality in the south are the main explanations of why the FRs are higher in the north and lower in the south. Mortality differentials among women have only a marginal impact.

Using data for 94 provinces, three periods (1971–1973, 1981–1983 and 1991–1993), and for men and women, we present an interesting picture of the geography of adult and elderly mortality by cause of death in Italy. This picture brings into focus the North/South gap that has yet again emerged, this time in gender differences in mortality. Particular attention is given to mortality from those causes that would appear to depend on the geographical context and that have a greater role to play in overall mortality differences. We then define which causes of death have changed the geographic pattern in the period considered. Lastly we study the relationship between mortality by cause and socio-economic, health care, environmental, cultural, and nutritional variables.

This article is a revision of the previous edition article by G. Santow, volume 15, pp. 10070–10075, © 2001, Elsevier Ltd.

Objectives: Neglecting the presence of unobserved heterogeneity in survival analysis models has been showed to potentially lead to underestimating the effect of the covariates included in the analysis. This study aimed to investigate the role of unobserved heterogeneity of frailty on the estimation of mortality differentials from age 50 on by education level. Design: Longitudinal mortality follow-up of the census-based Turin population linked with the city registry office. Setting: Italian North-Western city of Turin, observation window 1971-2007. Population: 391 170 men and 456 216 women followed from age 50. Primary outcome measures: Mortality rate ratios obtained from survival analysis regression. Models were estimated with and without the component of unobserved heterogeneity of frailty and controlling for mortality improvement over time from both cohort and period perspectives. Results: In the majority of cases, the models without frailty estimated a smaller educational gradient than the models with frailty. Conclusions: The results draw the attention of the potential underestimation of the mortality inequalities by socioeconomic levels in survival analysis models when not controlling for unobserved heterogeneity of frailty.

The dual task of describing the characteristic trends of mortality in Europe and of putting forward explanatory hypotheses is the main goal of this article....I attempt to analyze the health transition from 1910....The different steps in mortality trends both in quantitative terms and with regard to structural changes by age and cause are also analyzed and compared when possible to the far-reaching changes that marked the history of mortality in Europe. An attempt at synthesis is performed using the data on life expectancy at birth in 1910 until recent times. Particular focus will be placed on the more significant stages of the decline in mortality by age and cause of death using life tables constructed for the years prior to World War I (1910); those for the early 1930s...; for 1950...; data for the 1960s and 1970s...; and finally the latest available data to gain insight into the decline now in process. (EXCERPT)

C'est sans doute en matière de mortalité que le paysage dans lequel évoluent nos contemporains a le plus changé depuis les débuts de Population. L'espérance de la vie à la naissance s'est considérablement allongée, tant dans les pays en développement que dans les pays développés. Graziella Caselli, à partir d'une analyse du contenu des grandes revues démographiques, nous dresse une histoire, en forme de bilan, de la recherche démographique. Elle montre, en particulier, comment celle-ci s'est transformée en même temps que la mortalité elle-même et elle tente, ensuite, de décrire les voies dans lesquelles elle pourrait s'engager à l'avenir., Caselli Graziella. Parcours et étapes des études sur la mortalité dans la dynamique de la recherche démographique. In: Population, 50ᵉ année, n°6, 1995. Cinquante années de Population pp. 1519-1544.

SummaryThis study examines local heterogeneity in the aptitude of Sardinian mothers towards late reproduction, and explores its temporal persistence and association with both post-reproductive longevity and propensity to consanguineous marriage. Data on women's fertility from 1961 and birth records for 1980–1996 from Vital Statistics were analysed by means of the following indicators: the incidence of old mothers at last childbirth, female mortality (1980–2001) at 80 years of age and over and the proportion of consanguineous marriages (1930–1969). A variable kernel-smoothing method was used to create interpretable representations of the true spatial structure of the indicators, and to highlight areas of higher than expected intensity. In particular, an area of reproductive and post-reproductive longevity was identified where the traits combine with a higher tendency to relatedness. Intriguingly, this area corresponds approximately to the geographically and historically well defined central-eastern zone, which was the refuge of Sardinians during past invasions, and overlaps the Ogliastra region, which has been widely studied for its genetic homogeneity.

In the present study, we use the modified orphanhood method to analyse mortality differences by socio-economic status in Italy. This technique permits the indirect estimation of adult mortality from survey-based information on parents' survival in developed populations and helps to overcome several limitations of conventional studies on mortality differences by social class. We estimate a time series of life tables by education and occupation and analyse the differences in life expectancy by socio-economic status along with their changes between 1980-84, 1985-89, and 1990-94. Whereas mortality differences between the highest social class and the other socio-economic status groups increased among men, they decreased among women. We speculate about the reasons for these sex-specific trends and evaluate the application of indirect estimation techniques to the populations of developed countries.

This report describes the first stage of the age validation process of Italian supercentenarians. The process is still in progress and to date has only concerned supercentenarians deceased in the period 1969-2000. Of 35 potential supercentenarians included in the Italian National Institute of Statistics (Istituto nazionale di statistica, or Istat) database, 21 cases (three males and 18 females) are fully validated, seven cases refer to false supercentenarians—the error often being a misreported date of birth—and seven cases still remain unverified. The maximum age reached by the validated supercentenarians is 111, and the first case is recorded in 1973. In Italy supercentenarians have become a significant phenomenon only in the last few years.

Evolution in human life-history traits is influenced by environmental factors and, when genetic components underlie the relations, by micro-evolutionary forces. Age at reproduction is largely influenced by the familial cultural context and socioeconomic level, besides the maternal well-being and genetic background. The Sardinian population is characterized by historico-geographical isolation and differentiates from Italian mainland and other European populations in bio-demographic and cultural characteristics, among which the tendency to delay maternity persisting through generations. In our study, we investigated whether, in Sardinia, areas of "reproductive longevity" exist, where a higher-than-average incidence of late maternities combines with a lower-than-average cost in terms of perinatal death. Data from the Italian Central Institute of Statistics regard all 1980-1996 Sardinian births. Using spatial analysis of late maternity (proportion of babies born to mothers aged >=35 years) and associated perinatal mortality (proportion of babies stillborn and dead within 0-6 days born to mothers aged >=35 years), we aimed at singling out areas where the indicators run high and low, respectively. The perinatal mortality cost associated with the advanced maternal age [odds ratios (95% CI)] was evaluated through multiple logistic regression models. We identified central inland excess areas qualified by higher incidence of late maternities (27% vs. 22% in nonexcess area) and lower cost in perinatal mortality [OR=1.38 (1.04-1.84) vs. OR=1.74 (1.55-1.96) in nonexcess area]. In these "reproductive longevity" areas, the inbreeding coefficient was 3.7-fold higher than in the nonexcess areas, suggesting possible population homozygosity in genetic factors affecting the trait. Further and deeper investigations on biological and environmental determinants could focus on these target areas.

The contemporary world continues to register substantial progress in economic growth, abundance in production of food grains, and profound breakthroughs in medical technology and knowledge on diseases and healthcare. These are no mean achievements and there are reasons to further them, as they play important role in both reducing poverty and hunger, and improving the health and nutritional status of the population. Despite this progress and achievement, a number of regressive aspects also continue to plague many parts of the world and blight the lives of men and women in various ways. The manifestation and intensity of these aspects varies between regions and between countries within regions. Poverty, hunger, malnutrition and mortality are so inexorably intertwined that they reinforce each other and hinder human development and economic growth. Understanding the relationship between poverty, nutrition and mortality is a complex one and this relationship vary according to the social, economic and cultural environment. In order to further our knowledge on these important issues, a seminar titled “The Impact of Mortality as Both a Determinant and a Consequence of Poverty and Hunger: A Contribution to Achieving the First Millennium Development Goal (Eradicate Extreme Poverty and Hunger)” was held between February 23 and 25, 2005 in Trivandrum, India. The seminar was organised jointly by CICRED and the Centre for Development Studies (CDS) with financial support from UNFPA This book presents some of the papers offered at that conference with additional papers ‘invited’ in order to cover other regions and to fill the gap in certain issues. This volume covers Asia, the Pacific and Africa where nearly 90 percent of the world’s hungry people live. About 2 out of 5 under-five deaths occur in Sub-Saharan Africa and almost half of the world’s undernourished children live in South Asia.

We are here trying to measure the impact of each element of the total fertility, mortality and migration history of the cohorts concerned on population structure change. Computations are done for both France and Italy on population ageing during the last 30 years as well as until the end of the official population projections around 2040. Though the ageing effect of fertility decrease is usually emphasized, we can see here that the consequences of mortality change are at least equally (and sometimes more) important. The case of the Italian projections is particularly fascinating. Even if the very low fertility level of 1.4 children per woman is maintained until the year 2040, more than half the increase in the proportion of the population aged 60 and over (from 21% to 43% for females) would be due to mortality change and slightly less to fertility change.

Like any science focusing on man (either as an individual or as part of a group), demography is faced with the need to develop a systematic approach: its units of observation (individual or collective) are multidimensional systems, whose many components define a single entity, which takes decisions, experiences events and influences its environment. The various disciplines as we currently know them are simply different points of view from which we observe these units. Economics, sociology, epidemiology and medicine, the disciplines closest to demography from a thematic perspective, all face the same dilemma: in order to explain the behaviour of the unit studied, all dimensions of that unit must be taken into account, and no single dimension considered as exclusive (or more important than the others).The need for a multidisciplinary (or, more precisely, systematic) approach is not, therefore, unique to demography. It is, perhaps, simply more apparent, more acute in this discipline, for two reasons that can be seen as constraints, but also as opportunities, in that they strengthen the imperative to move beyond the classical approach. The first reason is the need to take both micro and macro dimensions into account. Demography, which is based upon a macro approach to the study of populations, has only recently begun to concern itself with micro (individual) and meso (family) units. Bringing these strands together is quite clearly vital (although moves to do so were late in coming, as indeed was the micro approach itself, if one considers the history of the discipline).The second reason arises out of the fact that with time, the events of specific interest to the demographer have lost much of their essentially biological nature and are increasingly matters of individual choice. They are, however, events of great significance in the life of an individual - birth of a child, migration, family formation, death - which are not the result of merely circumstantial choices (or situations), but rather milestones on a long "decision path" (or life course). Many different elements come into play (individual and collective, economic and social, cultural and biological, etc.), and it is often impossible - perhaps also ill-advised - to attempt to determine the specific part played by each.A multidisciplinary approach is thus vital to progress in demography, just as the advent of longitudinal methods has proven to be in recent years for the reconstruction of processes whose unfolding, on an individual timescale, as on a historical timescale, leads to certain demographic choices and events. The same applies today for the simultaneous consideration of micro and macro (and/or meso) levels when interpreting demographic behaviour.A further constraint - or opportunity - is the relative inadequacy of the theoretical corpus of demography, which favours an approach based on empirical observation. Such an approach does not, of course, allow one to dispense with a conceptual framework for analysing a phenomenon. On the contrary, a clear and well-structured theoretical framework with which to organize the system of relations governing the phenomenon is absolutely essential, even when collecting the initial statistics that will subsequently serve to describe its evolution and properties. What is often lacking is the grouping of sectorial hypotheses and theories into one coherent ensemble to be expressly adopted by those undertaking and initiating research. In one respect, the caution with which demographers have always approached the construction of theories reflects the realism of a discipline that, to build bridges between social and biological sciences, has always needed to be wary of partial approaches and the inadequacy of simple theories to resolve the complexity of the object of study. But this circumspection is liable to become a growing hindrance, as it quite clearly runs counter to the process of theory testing-appraisal-refutation that has been a driving force for progress in other fields, thanks notably to the passionate debates it has sparked (though such debate has not always been free from ideology and prejudice) (Popper, 1999)(1). …

On April 18, 2007 an international meeting on Pathophysiology of Ageing, Longevity and Age-Related Diseases was held in Palermo, Italy. Several interesting topics on Cancer, Immunosenescence, Age-related inflammatory diseases and longevity were discussed. In this report we summarize the most important issues. However, ageing must be considered an unavoidable end point of the life history of each individual, nevertheless the increasing knowledge on ageing mechanisms, allows envisaging many different strategies to cope with, and delay it. So, a better understanding of pathophysiology of ageing and age-related disease is essential for giving everybody a reasonable chance for living a long and enjoyable final part of the life.

Three dimensions of the survival curve have been developed: (1) “horizontalization,” which corresponds to how long a cohort and how many survivors can live before aging-related deaths significantly decrease the proportion of survivors; (2) “verticalization,” which corresponds to how concentrated aging-related (“normal”) deaths are around the modal age at death (M); and (3) “longevity extension,” which corresponds to how far the highest normal life durations can exceed M. Our study shows that the degree of horizontalization increased relatively less than the degree of verticalization in Hong Kong from 1976 to 2001. After age normalization, the highest normal life durations moved closer to M, implying that the increase in human longevity is meeting some resistance.

Barbi Elisabetta, Caselli Graziella, Vallin Jacques.- Trajectories of Extreme Survival in Heterogeneous Populations Recent gams in life expectancy among the elderly have noticeably contributed to increasing average life expectancy in developed countries. The old and oldest old are reaching thresholds that were unthinkable 30 or 40 years ago. Are recent gains due to increased longevity among a growing proportion of the population? Or are such gains the harbinger of new frontiers that may announce the further "extension" of the survival curve? Deeper comprehension of underlying mechanisms hinges on models that consider the impact of heterogeneity in individual frailty. In this paper, we analyse the mortality trajectories of French women born between 1820 and 1879. We applied a classic frailty model and a mixture frailty model accounting for individual differences both in the level of mortality and in the rate of aging. The survival trajectories obtained with these models were used to estimate the maximum life span. Moreover, a non-parametric approach was applied to female centenarians born in France between 1870 and 1879 to estimate the extreme age at death. Results confirm that population heterogeneity can be an important factor in the dynamics of mortality at the oldest ages. In particular, the mixture frailty model may fit the data better and estimate the possible maximum life span more accurately. A tendency towards an increasing human life span clearly emerges, without however establishing whether a limit in fact exists., Barbi Elisabetta, Caselli Graziella, Vallin Jacques.- Hétérogénéité des générations et âge extrême de la vie Les gains récents d'espérance de vie pour les personnes âgées ont considérablement contribué à l'augmentation de l'espérance de vie dans les pays développés. Les personnes âgées et très âgées atteignent des âges qui étaient inimaginables il y a 30 ou 40 ans. Ces progrès d'espérance de vie sont-ils dus à l'augmentation de la longévité d'une part croissante de la population? Ou bien s'agit-il des signes avant-coureurs de nouveaux sommets qui pourraient annoncer une « extension » de la courbe de survie ? Pour mieux comprendre les mécanismes enjeu, on doit faire appel à des modèles qui prennent en considération l'hétérogénéité de la fragilité individuelle. Nous analysons ici les trajectoires de mortalité de femmes françaises nées entre 1820 et 1879. Nous appliquons un modèle de fragilité classique et un modèle de fragilité combiné permettant de tenir compte des différences individuelles à la fois pour le niveau de mortalité et pour le rythme de vieillissement. Avec les trajectoires de survie ainsi obtenues, nous avons tenté d'estimer la durée de vie maximale. De plus, une approche non paramétrique a été appliquée aux femmes centenaires nées en France entre 1870 et 1879, afin d'estimer l'âge extrême au décès. Les résultats confirment que l'hétérogénéité de la population est sans doute un facteur important des dynamiques de la mortalité aux très grands âges. En particulier, le modèle de fragilité combiné pourrait permettre une meilleure adéquation avec les données et une plus grande précision de l'estimation de la durée de vie maximale. Nous voyons clairement émerger une tendance à l'augmentation de la durée de vie, sans que l'on puisse cependant établir l'existence ou non d'une limite., Barbi Elisabetta, Caselli Graziella, Vallin Jacques.- Trayectorias de supervivencia limite en poblaciones heterogéneas El aumento de la esperanza de vida de las personas mayores ha contribuido de forma significativa al aumento de la esperanza de vida total en los países desarrollados. Las personas mayores y las muy mayores están alcanzando limites de edad impensables hace 30 о 40 aiios., Barbi Elisabetta, Caselli G., Vallin Jacques. Trajectories of Extreme Survival in Heterogeneous Populations. In: Population (English edition), 58ᵉ année, n°1, 2003. pp. 43-65.

This paper considers the issue of actuarial fairness of the new Italian public pension system in view of the recent trends in old-age mortality and the survival differences by gender, birth cohort and region of residence. After reviewing the secular trends in elderly mortality in Italy, and the evolution of regional differences in survival over the last three decades, we evaluate the impact, on the conversion factors introduced by the Dini reform, of a further decline in elderly mortality over the next few decades. We compute the conversion factors using a close approximation to the unknown formula employed in the Dini reform but allowing for gender- and region-specific survival probabilities. Our results leave no doubt about the importance of frequently updating the conversion factors in the light of the rapid increase in elderly survival. The paper also quantifies to what extent gender- and region-specific conversion factors may differ from their currently legislated values, that only vary by age. Finally, we recognize that the actuarial fairness of the system introduced by the recent reform can only be guaranteed on average and that, in the presence of a heterogeneous population of individuals that differ considerably in their mortality prospects, the current system implies a substantial degree of redistribution from high-mortality groups (typically characterized by low income and low wealth) to low-mortality groups (typically characterized by high income and high wealth).

Recent mortality studies analyse period tables much differently than was previously the practice. Going back to the last century, a period which witnessed major, rapid progress in survival, thanks to period data mortality, trends could be described so as to interpret these in relation to socio-economic and medical-health developments. When mortality was still very high and gains in life expectancy were mainly attributable to the fall in mortality among infants and youth, by analysing period data, the extent to which a country made progress in health and hygiene could be assessed and this then compared with developments in other countries. Currently, in developed countries, where mortality at different ages is the lowest ever, it is no easy task to analyse recent trends and differences merely on the basis of a cross-sectional analysis. Even from a prospective outlook, future horizons would be somewhat curtailed if analysis were to be limited to a purely transversal vision of mortality data. This is because the period of major achievement has most likely ended. Further gains, besides being contained, increasingly depend on the life histories of cohorts, and particularly on their ability and willingness to adopt healthier life-styles which are more conducive to longer life-expectancy.