Why People Die Before They Expect To

David Hemenway and his son Brett, a mathematician at the University of Pennsylvania, published their first article together on the simple fact that your (conditional) life expectancy is always positive when you die.  Indeed, using life expectancy tables, the average additional expected lifespan at the time of death in the US is close to 12 years.  In some countries, the average number of years remaining at the time of death may be more than the average expected lifespan at time of birth!  The article, “Why People Die Before They Expect To” by Brett and David Hemenway appears in Mathematics Magazine 2018; 91:171-81.