送交者: mangolasi 于 2006-2-02, 16:25:17:
回答: Suppose you use 1/3 of the time to work, wasguru's calculation is correct. 由 mangolasi 于 2006-2-02, 16:12:10:
Some back of envelope calculation.
wasguru's calculation of miner's prob. to survive to 60 is .838, so roughly .012 lost compared to general case.
I suppose only .7^5=.16807 people survive to 65 (very deep decline), and every year only 70% >60 people survive to the next year.
The expected life lost for miner would be:
.012*(60+.7*61+.7^2*62+.7^3*63+.7^4*64+.7^5*65)
[1] 2.171759
What happen when this danergous job happens in your youth? You loses same .012 chances to survive to 45 (your retire age), hence even less chance compared to other people to survive 60 (looking at your 20s, not at your retirement).
What happens when the survive rate after 60 >.7? the lost of expected life is larger. So this moderate 2.17 yrs is only a conservative estimation.