MGT of America was commissioned to carry out a study of the economic impact of the smoking ordinance on restaurant sales and mixed beverage sales in Houston, TX.
Their conclusion was that the smoking ordinances did not appear to carry adverse outcomes for the restaurant and drinking establishment sector in aggregate.
Obviously this was not a study on pool halls.
http://www.houstontx.gov/health/Houston Smoking 2nd Update.pdf
A separate study was done on pool halls because they wanted to know how many cigarettes were bummed off someone else.