Identifying the Ruptures Shaping the Segmented Line of the Secular Trends in Maximum Life Expectancies

In their 2002 paper, Oeppen and Vaupel showed that the trend in the highest life expectancy reached each year in the world follows a straight line with a 25% gradient, since 1841. If we had been nearing a limit, they claimed, we would have seen a flattening of the curve over recent decades. As this is not the case, there is no reason to believe that progress in life expectancy will stall in the near future.

In a more recent paper, Vallin and Meslé, by looking at more data and scrutinizing the data quality, recognized that maximum life expectancies follow a succession of four segments with associated different slopes. This indicates that, at each stage, new tools for health improvements triggers a new pace in life expectancy increase.

However, Vallin and Meslé’s identification of the time cuts was intuitive, simply suggested by the general shape of the cloud of points.

In collaboration with Vallin and Meslé from the Institut National d'Etudes Démographiques, I aim to check the existence of eventual cuts, their number and their timing. Segmented regression provides an elegant framework and will be employed to statistically identify possible ruptures in the time series of maximum life expectancies. We also intend to pursue further analysis by age which will shed light on the determinants of the eventual changes in the gradient of the life expectancy improvement.

We present our ideas at the 2012 European Population Conference; here you find the extended abstract and the associated slides of the work: Identifying the Ruptures Shaping the Segmented Line of the Secular Trends in Maximum Life Expectancies.