KohortenTafeln

KohortenTafeln, or cohort life tables, are a tool in demography and actuarial science that summarize the mortality experience of a birth cohort as it ages. Instead of describing mortality at a single point in time, they trace a group born in the same year from birth onward, recording the number alive at the start of each age interval and the deaths that occur within it.

They yield measures such as the number alive at the beginning of each age interval, the number of deaths in the interval, and the probability of dying between ages. From these data, life expectancy at age x and the survival function for the cohort can be derived. The central feature of KohortenTafeln is that mortality conditions may change over calendar time, and the tables reflect the experiences faced by the cohort as it ages, rather than the mortality rates prevailing in a fixed year.

Construction can be based on longitudinal data that follow a real cohort over time, or on synthetic methods that interpolate from available information. They are contrasted with period life tables, which assume that the age-specific mortality rates observed in a given calendar year apply to a hypothetical cohort born that year. KohortenTafeln are thus especially useful for analyzing historical mortality changes, forecasting long-term survival, and informing pension or social security planning.

Limitations include data requirements, the need for extended observation, and potential biases from incomplete follow-up or migration. They provide a deeper view of aging and mortality dynamics across generations and complement period life tables.