The relationship between longevity and lifespan variation

This paper contributes to the current discussion on longevity by investigating the long-term dynamics of life expectancy, and lifespan variation. The analysis provides the expectiles of the life expectancy distribution, relating them to the values of lifespan variation measured by Keyfitz's index. This allows us to study both the location and the spread of the life expectancy over time in light of the mortality compression process. Using cointegration analysis, we also explore the long-term dynamics between the two longevity measures in some selected developed countries. Overall, we found evidence of a negative relationship between longevity and lifespan variation, thus confirming previous studies. While, by detecting untracked behaviors taking into account the country-specific contribution over time, this study suggests that the strength of this relationship varies across life expectancy distribution' sections in which the country is located (i.e. specifically expectile), and how fast the country converges towards best performances.