 A study by the University of Hamburg (Ahlfeldt and Maennig 2010) demonstrates, that the smoking ban had, if any, only short run impacts on bar and restaurant revenues.In the medium and long run no negative effect was measurable.The results suggest either, that the consumption in bars and restaurants is not affected by smoking bans in the long run, or, that negative revenue impacts by smokers are compensated by increasing revenues through non-smokers.