Flaw in life expectancy theory
The flaw in such reasoning becomes apparent when one remembers that life expectancy is based on averages. Given that some 50-year-olds die before they reach 60, the calculation for the 60-year-old "survivors" is bound to yield an enhanced figure.
If one wanted to find out whether early retirement per se enhanced the average teacher's life expectancy one would need the life expectancy figures for, say, teachers aged 50 who retire, to compare with teachers aged 50 who work on for at least several years.
PHILIP GOGGIN Senior lecturer Crewe School of Education Manchester Metropolitan University