Mortality compression in period life tables hides decompression in birth cohorts in low-mortality countries

Dalkhat M Ediev


The rapid increase in human longevity has raised important questions about what implications this development may have for the variability of age at death. Earlier studies have reported evidence of a historical trend towards mortality compression. However, the period life table model, commonly used to address mortality compression, produces a compressed picture of mortality as a built-in feature of the model. To overcome this limitation, we base our study on an examination of the durations of exposure, in years of age, of birth cohorts and period life tables to selected short ranges of the death rate observed at old age. Overall, old-age mortality has been decompressing, cohort-wise, since the 1960s. This process may further indicate good prospects for ever-decreasing mortality. In the future, deaths may not be concentrated within a narrow age interval, but will instead become more dispersed, though at ever later ages on average.

Dalkhat M. EDIEV, Senoir Sceintist, Wittgenstein Centre for Demography and Global Human Capital (IIASA, VID/ÖAW, WU), International Institute for Applied Systems Analysis and Vienna Institute of  Demography/Austrian Academy of Sciences, Austria. E-mail:


mortality compression; cohort analysis; lifespan

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ISSN: 2035-5556

Reg. Tribunale di Roma n. 3321/54