Effectiveness of Enforcement
"Similar evidence of the drug war’s failure is provided by US drug surveillance data. For example, from 1981 to 2011, the budget of the US Office of National Drug Control Policy increased by more than 600 percent (inflation-adjusted). However, despite increasing annual multibillion dollar investments in drug control, US government data suggest an approximate inflation- and purity-adjusted decrease in heroin price of 80 percent, and a greater than 900 percent increase in heroin purity between 1981 and 2002, clearly indicating that expenditures on interventions to reduce the supply of heroin into the United States were unsuccessful."
"The War on Drugs and HIV/AIDS: How the Criminalization of Drug Use Fuels the Global Pandemic," Global Commission on Drug Policy (Rio de Janeiro, Brazil: June 2012), p. 11.