Period life expectancy over- or understates current mortality conditions in the presence of tempo effects
During the last decade a new interpretation problem of trends in period life expectancy has been discussed in the demographic literature. This interpretation problem is related to socalledtempo effects, which occur if large numbers of deaths are suddenly postponed. In such conditions the life table inflates the average lifespan gained in the population since it weights avoided deaths with the full remaining life expectancy. This paper explains how such effects occur and indicates their relevance for population health researchers. An illustrative example is given based on the observation of a sudden upturn of life expectancy in East Germanyfollowing its reunification with West Germany. Although there is no standard procedure to detect and remove tempo effects, we recommend that the assumptions of the life table, in this case about the remaining life expectancy of avoided deaths, are carefully evaluated in all applications. Interdisciplinary efforts to develop models to detect and quantify tempo effects from life expectancy calculations should be put on the research agenda.