Increments to life and mortality tempo

This paper introduces and develops the idea of “increments to life.†Increments to life are roughly analogous to forces of mortality: they are quantities specified for each age and time by a mathematical function of two variables that may be used to describe, analyze and model changing length of life in populations. The rationale is three-fold. First, I wanted a general mathematical representation of Bongaart’s “life extension†pill (Bongaarts and Feeney 2003) allowing for continuous variation in age and time. This is accomplished in sections 3-5, to which sections 1-2 are preliminaries. It turned out to be a good deal more difficult than I expected, partly on account of the mathematics, but mostly because it requires thinking in very unaccustomed ways. Second, I wanted a means of assessing the robustness of the Bongaarts-Feeney mortality tempo adjustment formula (Bongaarts and Feeney 2003) against variations in increments to life by age. Section 6 shows how the increments to life mathematics accomplishes this with an application to the Swedish data used in Bongaarts and Feeney (2003). In this application, at least, the Bongaarts-Feeney adjustment is robust. Third, I hoped by formulating age-variable increments to life to avoid the slight awkwardness of working with conditional rather than unconditional survival functions. This third aim has not been accomplished, but this appears to be because it was unreasonable to begin with. While it is possible to conceptualize length of life as completely described by an age-varying increments to life function, this is not consistent with the Bongaarts-Feeney mortality tempo adjustment. What seems to be needed, rather, is a model that incorporates two fundamentally different kinds of changes in mortality and length of life, one based on the familiar force of mortality function, the other based on the increments to life function. Section 7 considers heuristically what such models might look like.adult mortality, increments to life, length of life, life expectancy at birth, mortality, mortality measurement, mortality tempo, mortality tempo adjustment, period-cohort relationships, risk of death, robustness of Bongaarts-Feeney method, tempo adjustment

The Quantum and Tempo of Life-Cycle Events

This study develops and applies a general framework for the analysis of the period quantum and tempo of life-cycle events, extending methods developed previously by the authors. The existence of tempo distortions is demonstrated in selected period quantum measures such as the total fertility rate and in period tempo measures such as life expectancy. A tempo distortion is defined as an inflation or deflation of a period quantum or tempo indicator of a life-cycle event, such as birth, marriage, or death, that results from a rise or fall in the mean age at which the event occurs. Period measures derived from life tables are also found to be subject to tempo distortions. Methods to remove these tempo distortions are then developed and applied.

The quantum and tempo of life-cycle events

This Research Division working paper develops and applies a general framework for the analysis of the period quantum and tempo of life-cycle events, extending methods developed previously by the authors. The existence of tempo distortions is demonstrated in selected period quantum measures such as the total fertility rate and in period tempo measures such as life expectancy. A tempo distortion is defined as an undesirable inflation or deflation of a period quantum or tempo indicator of a life-cycle event, such as birth, marriage, or death, that results from a rise or fall in the mean age at which the event occurs. Period measures derived from life tables are also found to be subject to distortion. Methods to remove these tempo distortions are then developed and applied

Mortality Tempo: A Guide for the Skeptic

Die Idee von Tempo-Effekten in der Mortalität basiert unmittelbar auf der Idee der Tempo-Effekte in der Fertilität, die auf den von Norman B. Ryder vor einem halben Jahrhundert publizierten Arbeiten aufbaut und nunmehr weithin bekannt und akzeptiert ist. Angesichts der Tatsache, dass sich die Ansätze im Wesentlichen gleichen, ist es verwunderlich, dass Tempo-Effekte in der Mortalität erst vor kurzem thematisiert wurden und bis heute noch nicht allgemein anerkannt sind. Eine mögliche Erklärung dafür könnte sein, dass die Auswirkungen von Tempo-Effekten in der Mortalität scheinbar im Widerspruch zu den etablierten Modellierungs- und Analyseverfahren für Sterblichkeits- und Bevölkerungsdynamiken stehen. In diesem Beitrag wird ein diskreter Ansatz zur Beschreibung und Analyse von Tempo-Effekten in der Mortalität entwickelt. Der diskrete Ansatz ist zwar mathematisch wenig anspruchsvoll, dafür aber sehr überzeugend. Er wird in diesem Beitrag zum Beispiel für die Bestimmung altersspezifischer Tempo-Effekte verwendet. Der Schwerpunkt des Beitrags liegt auf der Messung der Lebensdauer empirischer Bevölkerungen. Dabei wird gezeigt, dass jede empirische Bevölkerung durch eine angemessen konstruierte Modellpopulation approximiert werden kann.The idea of mortality tempo effects derives from the idea of fertility tempo effects, which were introduced by Norman B. Ryder and are widely known and accepted. Given the essential similarity of the ideas, it might be regarded as curious that mortality tempo effects have only recently been recognized and are not as yet generally accepted. The explanation for this may be that mortality tempo effects have implications that seem to be at variance with established ways of modeling and analyzing mortality and population dynamics. This paper develops a discrete approach to describing and analyzing mortality tempo effects. The discrete approach is mathematically undemanding, yet powerful. It is used here, for example, to define age-specific tempo effects. The focus of this work is the measurement of length of life in empirical populations. It is shown that any empirical population may be approximated by a suitably constructed discrete model population

Estimacion de tasas de mortalidad infantil a partir de informacion de sobrevivencia de hijos clasificados por edad de la madre

Incluye BibliografíaTraducción del inglésEl metodo de Feeney utiliza la misma informacion que otros similares (Brass, Sullivan, Trussell), es sencillo de aplicar y provee estimaciones de mortalidad infantil hasta 15 anos antes del censo o encuesta en que se recoge la informacion. Aunque considera cambios en la mortalidad, no precisa conocer la tasa de cambio. Las hipotesis del metodo son: a) tendencia lineal del descenso de la mortalidad infantil, b) comportamiento de la mortalidad de la poblacion de acuerdo a una tabla modelo, c) ausencia de mortalidad diferencial por edad de la madre. Empiricamente resulta que esas tendencias lineales se intersectan en la cercania de un punto, cuyas coordenadas estiman la tasa de mortalidad infantil y el numero de anos anteriores al censo. La aplicacion se realiza con datos provenientes de los censos de 1968 y 1973 en las islas Gilbert y Ellic

How long do we live?

Period life expectancy is calculated from age-specific death rates using life table methods that are among the oldest and most fundamental tools of demography. These methods are rarely questioned, much less criticized. Yet changing age patterns of adult mortality in contemporary countries with high life expectancy provide a basis for questioning the conventional use of age-specific death rates and life tables. This paper argues that when the mean age at death is rising, period life expectancy at birth as conventionally calculated overestimates life expectancy. Estimates of this upward bias, ranging from 1.6 years for the United States and Sweden to 3.3 years for Japan for 1980-95, are presented. A similar bias in the opposite direction occurs when mean age at death is falling. These biases can also distort trends in life expectancy as conventionally calculated and may affect projections of future trends in period life expectancy

Social determinants of male health: a case study of Leeds, UK.

BACKGROUND: The social determinants of health have a disproportionate impact on mortality in men. A study into the state of health of the male population in Leeds was undertaken to guide public health commissioning decisions. This paper reports on the data relating to the social lives of men. METHODS: A cross-sectional study was undertaken, comprising descriptive analysis of data relating to educational attainment, housing, employment (including benefit claimants), marital status and relationships. Data was considered for the whole city and localised at the Middle Super Output Area (MSOA) level and mapped against the Index of Deprivation. RESULTS: Boys' educational attainment was found to be lagging behind girls' from their earliest assessments (Early Years Foundation Stage Profile, 46% vs. 60%, P = 0.00) to GCSEs (53% vs. 63%, P = 0.00), leaving many men with no qualifications. There were 68% more men than women identified as being unemployed, with more men claiming benefits. Men living in social housing are more likely to be housed in high-rise flats. Almost 50% of men aged 16-64 are single, with 2254 lone fathers. CONCLUSIONS: There appears to be a lack of sex/gender analysis of current cross city data. In areas of deprivation a complex picture of multiple social problems emerges, with marked gender differences in the social determinants of health, with males seeming to be more negatively affected. There is a need for more focused planning for reaching out and targeting boys and men in the most deprived inner city areas, so that greater efficiency in service delivery can be obtained

Barbarians at the British Museum: Anglo-Saxon Art, Race and Religion

A critical historiographical overview of art historical approaches to early medieval material culture, with a focus on the British Museum collections and their connections to religion