Comment by djoldman

Initially I assumed it to be negligible but the numbers are actually very close!

I calculate around a 3% drop in speed (from 60mpg) for holding an average sized book out of the window. That's surprising to me.

It's not quite right to use hazard ratios to calculate life expectancy. But if we force it, it looks like being in the top 20% of "regular" sleepers compared to the bottom 20% confers 3-4.5 years of extra life (from birth, assuming everything else equal, assuming USA, etc.). That's 3.8%-5.7% more life (79 year life expectancy at birth in the USA as of 2025). So the numbers are actually close.

I made a bad analogy :)

But you get my point!