If you can't isolate other factors the stats treatment becomes meaningless. Since there is concentration of crime in prohibition era in major urban areas you can by the same token observe a very strong correlation between number of restrooms in the city and a homicide rate or any other meaningless factor related to population size.
Wasnt prohibition everywhere in the States, while lead pipes weren't?
Can you show a study based on 100 year old data that isn't flawed? I don't get what you think they should have done?
