Your back of the envelope estimate is incorrect
You are wrong. My back of the envelope estimate is pretty accurate.
Here is an estimate of the average age of murder victims in the US for 1998.
cambridgepolice.org
The average age of male murder victims is mid-twenties, the average female forty. Given that 77% are male and 23% female, average age is 28.5 years.
Now lets see how such a murder rate will affect a population of 100,000 that lived for, say, 80 years. Assuming a murder rate of 4 per 100,000 per year (the excess rate of the US over other industrialized countries), after 80 years 80*4 (320) of the 100,000 would have been murdered at an age of 28 (the average), while the rest would have died at 80. Therefore, the average life span would be:
(320*28 + 99,680*80)/100,000 = 79.83
Theferore, a murder rate of 4 per year per 100,000 reduces the average life span of this population by 0.17 years or 2.04 months. |
