"For the last ten years, the Observatoire français des drogues et des toxicomanies (OFDT, or the French Monitoring Centre for Drugs and Drug Addiction) has repeatedly worked on estimating the social cost of licit and illicit drugs. The first study (Kopp et al. 1998) dates back to the 1990s and examined the possible calculation methods. The initial estimates were presented in the Kopp and Fénoglio report (Kopp et al. 2000) on Le coût social des drogues (the social cost of drugs). This initial work estimated the annual costs of the illicit drugs to society to be €2,035.24 million. Regular estimates have been carried out since then. There are two reasons for the need to continually re-estimate these figures: the appearance of new data that were initially unavailable (e.g. treatments for certain diseases) and the need to consider new calculation methods. Hence, the 2006 study assessed the social cost of illegal drugs to be €2,824.44 million in 2003 (Kopp et al. 2004). Compared to the 2000 estimate, the social cost of illicit drugs was only multiplied by a factor of approximately 1.39."

Source

l'Observatoire francais des drogues et des toxicomanies (OFDT), "2012 National Report (2011 data) to the EMCDDA by the Reitox National Focal Point: France: New Development, Trends and in-depth information on selected issues (Saint-Denis, France: OFDT, 2012), p. 33.
http://www.ofdt.fr/BDD/public…