방법 비교

	Abridged Life Table	Life Expectancy Decomposition
분야	Social Epidemiology	Social Epidemiology
계열	Process / pipeline	Process / pipeline
기원 연도	1984	1984
창시자	Chin Long Chiang; Samuel Preston, Patrick Heuveline & Michel Guillot	Eduardo E. Arriaga; John H. Pollard
유형	Demographic estimation pipeline for mortality and survivorship	Demographic decomposition pipeline for differences in a summary measure
원전	Chiang, C. L. (1984). The Life Table and Its Applications. Malabar, FL: Robert E. Krieger Publishing. ISBN: 9780898745702	Arriaga, E. E. (1984). Measuring and explaining the change in life expectancies. Demography, 21(1), 83-96.
별칭	Abridged Life Table Method, Grouped-Age Life Table, Chiang Life Table, nMx to nqx Life Table	Life Expectancy Decomposition Methods, Decomposition of Changes in Life Expectancy, Age and Cause Decomposition of Life Expectancy, Stepwise Life Expectancy Decomposition
관련	3	4
요약	The abridged life table is the workhorse of demography and population health for summarizing the mortality experience of a population in a single, age-grouped table. Instead of a single-year (complete) life table, it works on broad age intervals — typically <1, 1-4, then five-year groups up to an open-ended oldest interval — which makes it robust when deaths or populations in single years of age are sparse or noisy. The construction propagates a small set of inputs, the age-specific death rates nMx, through a chain of columns: the probability of dying nqx, the survivors lx, the deaths ndx, the person-years lived nLx and Tx, and finally life expectancy ex. Chiang's 1984 treatment supplied the standard estimator and the fraction-of-interval term ax that controls how person-years are allocated within each interval, while Preston, Heuveline and Guillot's 2001 textbook codified the modern pipeline used across demography and epidemiology.	Life-expectancy decomposition answers a question that a single number cannot: when life expectancy rises over time, or differs between two populations, exactly which ages and which causes of death are responsible? The family of methods takes two life tables and splits their gap in e0 (or ex at any age) into additive contributions from mortality differences in each age interval, with the contributions summing exactly to the total gap. Eduardo Arriaga's 1984 stepwise discrete method became the field standard because it is exact, intuitive, and easy to extend to a cause-of-death breakdown, separating a 'direct' effect of changed survival within an interval from an 'indirect plus interaction' effect that the change propagates to later ages. John Pollard's continuous formulation expresses the same decomposition as an integral of age-specific mortality differences weighted by their leverage on life expectancy, providing the theoretical underpinning and a cross-check. This page treats the general decomposition pipeline; the dedicated Arriaga and Pollard pages cover each estimator in depth.