Alcohol -> drink and drive -> don't die yourself, but WHOOPS, you just killed a pedestrian -> the statistics give the cause of death as "car accident" rather than "alcohol" -> longevity
The only way that would contribute to the total mortality rate for drinkers being lower than for non-drinkers would be if I'm more likely to kill a pedestrian given that the pedestrian is sober than given that the pedestrian is drunk.
(OTOH, an effect such as “I'm (going to get) drunk, so I'm not driving tonight -> I'm walking back home rather than driving to there -> I'm less likely to die walking a mile than driving a mile” would be in the right direction, though --I guess-- much smaller than other effects. My money's on the biggest effect being the one about income.)
Apparently walking drunk is actually eight times more dangerous (per mile traveled) than driving drunk. So we would not expect moderate drinkers to have lower death rates due to walking home after drinking - if anything, this would increase their death rate.
My roommate recently sent me a review article that LW might find interesting:
Personal observation says that LWers tend not to drink very much or often. Perhaps that should change, to the degree suggested by the article?
Full article here.