[Rapid increase in maximal country specific life expectancy across cohorts]

Linear increase in the best-practice (maximal among countries) life expectancy, known as the Oeppen-Vaupel line, is the most demonstrative image of longevity progress. This study is devoted to the analysis of trends in best-practice life expectancy across cohorts born in 1870 to 1950. Other than the conventional period life expectancy, cohort life expectancy measures the lifetime of real individuals from the population under consideration. Since mortality is mostly decreasing with time, period life expectancy in a given year is usually lower than cohort life expectancy for people born in the same year. The corresponding gap between period and cohort life expectancies increases with time. Our analysis is based on data for 24 developed countries from the Human Mortality Database for the period 1870 to 2008. To estimate life expectancy for non-extinct cohorts, we apply the Lee-Carter model to extrapolate mortality rates until the year 2050. The annual increase in the best-practice cohort life expectancy across cohorts born in 1870 to 1950 is 0,43 year, while the annual increment in the period life expectancy across the same range of years is equal to 0,28 year. The best-practice cohort life expectancy has increased from 53,7 years in 1870 to 83,8 years in 1950. During this time the gap between period and cohort life expectancies has increased from 1,2 to 10,3 years. Cohorts born in 1920 to 1950 will live longer than one can expect by looking at respective period mortality patterns. For these cohorts, the longest part of their additionally gained lifetime will be spent at ages 65 and older. This substantially changes the distribution of human lifetime among different stages of the life cycle.