"Neighbourhood attitudes and perceptions. Surveys of local residents and businesses, as well as registers of complaints made to the police, generally show positive changes following the establishment of consumption rooms, including perceptions of decreased nuisance and increases in acceptance of the rooms. Police, too, often acknowledge that consumptions contribute to minimising or preventing open drug scenes.
"Open drug scenes and police policy. There are instances where consumption rooms have been blamed for increasing public nuisance, including open drug scenes and dealing. These arose where police actions in other areas had the effect of relocating drug markets and open scenes.
"Pull effect. Available evidence is not sufficient to draw conclusions on whether consumption rooms exert a 'pull-effect' by attracting drug users from other areas, thus adding to the situation already created by established drug markets. Attempts to decentralise drug scenes by dispersing consumption rooms have not led to increased nuisance around the rooms. However, they have not attracted large numbers of clients either."
Hedrich, Dagmar, "European Report on Drug Consumption Rooms" (Lisbon, Portugal: European Monitoring Centre on Drugs and Drug Addiction, February 2004), p. 81.