The End of Life Expectancy Increase? An analysis of life expectancy increases and the limited life span (LLS) and radical life span (RLS) models

<p dir="ltr">While life expectancy has increased significantly over the decades since 1900, the increases have slowed in the 2010 to 2024 period compared to the 2004 to 2010 period for many developed countries. For less developed parts of the world, life expectancies have kept increasing. Just over half of the developed OECD nations have experienced slowdowns in their life expectancies, with the U.S. and the U.K. seeing the largest slowdowns, with both countries suffering a decade of early deaths. There is the question of whether life expectancy will keep getting longer, even if it is slowing, and there are two ideas on this question. <i>First</i>, there is the limited life span (LLS) model, which suggests that there is a limit to how long human lives can be extended. <i>Second</i> there is the radical life span (RLS) model, which suggests that there are effectively no limits as long as medicine and technology keeps improving life spans. One accepted metric of whether we live with limited life spans or with radical life spans is the change in life expectancy at birth, and this is called <i>e</i>_<em>o</em>. That is, if year-over-year <i>e</i>_<em>o</em> is greater that 0.3 years then it is considered that radical life expectancy change has or is occurring. Using this base metric we can identify trends over time and any decennial periods where <i>e</i>_<em>o</em> exceeds 3 years or more would indicate that the RLS model is functioning over the LLS model. When life expectancy data per decade are calculated and graphed LLS and RLS can be identified as longevity generations. In this paper such an analysis is undertaken, and the results indicate that we have entered a period of LLS that appears to be destined to last at least until the end of this century.</p>