Today is inauguration day. Donald Trump will officially be the 45th President of the United States of America. Many have pointed out that Trump is the oldest president (slightly above 70 years of age). I disagree.

Old is not a “purely” absolute concept. Advances in living standards mean advances in our ability to live longer lives. Not only do we live longer lives than in the past, but at any point in our life, our health is better. Someone who reached 65 years of age in 1900 probably did not have the same health prospects as someone who reaches that age today. Basically, the “quality” of old age has increased over time (see this great book on the economic history of aging). So, when people say “old”, I ask “old as compared to what”.

To meet that test, I took the CDC data on life expectancy as well as soon historical database  from 1900 to today. I combined it with David Hacker’s work on life tables in the US from 1790 to 1900 which can be found in this article of Historical Methods.  Hacker’s data concerns only the white population. I took only the age expectancy at birth of males. Then, I plotted the age of the president at the time of inauguration as a share of the life expectancy at birth (E0). This is the result:

As one can see, the age of presidents as a share of life expectancy is falling steadily since the early 1900s. In this light, Donald Trump is not the oldest president. In fact, the oldest president is …. drumroll…James Buchanan (1.85 times the life expectancy of white males at birth). Moreover, in this light, the youngest president at inauguration is not Teddy Roosevelt (Kennedy was the youngest elected). Rather, the youngest is Barack Obama followed very closely by Bill Clinton and John F. Kennedy.

I find this post to be interesting as it shows something more important in my eyes: how the poorest in society have done. Presidents have generally stemmed from the top of the income distribution. Over time, the ages of presidents at inauguration (in absolute terms) has not followed any clear trend. The drop seen in the graph above is entirely driven by increases in the life expectancy of the “average” American. In a certain way, it shows that the distance between that “Joe the Plumber” and the “Greatest Man in America” (huh…Lord Acton anyone?) seems to be diminishing over time.