Cohort life expectancy is an important but rarely used indicator of mean longevity. In this paper, we show that there are specific advantages in lagging this indicator in time by its own value, an approach termed Lagged Cohort Life Expectancy (LCLE). We discuss the usefulness of LCLE as an indicator for tracking progress in mean longevity and introduce a new interpretation of LCLE as a reference age separating 'early' deaths from 'late' deaths, or, equivalently, as the age above which individuals in a population can be considered 'above-average' survivors. Using data from 15 countries in the Human Mortality Database, we show that current LCLE can be estimated with a relatively high degree of certainty, at least in these low-mortality populations. Results shed new light on levels and trends in mean longevity in these populations.
Keywords: cohort; life expectancy; mathematical demography; mortality; mortality forecasts; period.