Im sure a fair number of them would. it looks like about 1/2 of heavy drinkers would dissapear if that happened.
OK. This all assumes:
(1) The heavy drinkers make up the critical bulk of the bar's turnover;
(2) Smokers really do make up half the heavy drinkers;
(3) That, if smoking is banned, they will never EVER buy another drink there.
But...
(1) No proof this is so. And I would suggest that the bulk of any bar's turnover is made up from "the regulars", not the heavy drinkers (who I suspect number only a few).
In Australia, when smoking was banned, bars actually increased their custom, and diversified it too, by offering more than just a watering hole. They now offer good food (many are restaurant quality), better entertainment, gambling, conferencing, etc, etc. They are packed...far more than they used to be.
(2) Again, no proof this is so. And even if so, smokers would also number among the not-so-heavy drinkers.
(3) Proven wrong by facts. Heavy drinkers who are smokers simply will simply not smoke while drinking, but they WILL keep on drinking! The heavy drinkers are a dedicated lot - they will gladly forgo the cost and time for a drag on a ciggie if it gives them more drinking!
In summary, I'm not seeing any proof yet of the original assertion that smoking bans alone cause bars to go bankrupt. Bad management, poor operations or health issues, lack of business imagination, failure to adapt and improve, successful competition, etc, WILL cause bars to go bankrupt. Perhaps these issues had more to do with it entirely, n'cest pas?