Back in September
a PSC In The News reference
"Study Finds No Overall Negative Impact on Bars and Restaurants from Michigan's Dr. Ron Davis Smoke-Free Air Law" - Michigan Department of Community Health. 09/17/2012.
Analyzing 2006-2011 sales tax collections from Michigan bars and restaurants -- as well as from Club Keno sales -- Helen Levy found no significant negative sales effects of Michigan's 2010 smoking ban.