text: Life expectancies are averages. That means that you have a 50% chance of exceeding average life expectancy, and a 50% chance of not reaching it. "Ken's ancestors" is not a statistically valid sample. 
  
  Life expectancies are increasing, and a bunch of nascent biotechnologies suggest that life expectancies will increase A LOT in the near future. That factor, which Vettese ignored, weighs very heavily in my mind in favour of deferring my CPP and maximising the monthly benefit. I might well be able to start at age 70 and collect for many decades.