(1) @DrMarkThornton You say that prohibition in 1920 caused an increase in homicide, but it looks to me more like random variation with murder rates returning to their levels from a few years earlier. And we'd need better evidence to test causality. Research that uses local... 
(2) local variation in the timing of prohibition laws suggests that it decreased mortality suggesting that any rise murder was outweighed by health improvements. You also say that changes in alcohol consumption were small, but most estimates I've seen...
(3) suggest that it was pretty significant with respect to overall consumption and alcohol relates illnesses. Not sure how much of this is causal though since there was a cultural movement against alcohol coinciding with prohibition laws.
The positive..
nytimes.com/1989/10/16/opi…
The positive..
nytimes.com/1989/10/16/opi…
(4) health effects of alcohol prohibition mirror research on contemporary local bans on trans-fats which find that such laws have significantly improved heart health. For these reasons, though I don't support banning alcohol, I felt you were to pessimistic about the positive...
(5) effects of prohibition. I'm no expert on this though, and would be interested to hear your thoughts on these counter points, as you've probably heard them before.
