The following an excerpt from a report by the Office of National Drug Control Policy that explains that most of the data that favors Portugal’s decision to decriminalize drug consumption in 2001 comes from a single report conducted by the Cato Institute. This source explains the limitations of the analysis Cato Institute such as the study only focusing on certain age groups whose drug consumption decreased while ignoring other age groups where drug use increased. The report also explains that this report relies heavily on lifetime dependent data. This report only focuses on the effects of drug consumption, but the effects on violence and organized crime are not reported on.
“The Cato Institute report does not present sufficient evidence to support claims regarding causal effects of Portugal’s drug policy on usage rates. More data are required before drawing any firm conclusions, and ultimately these conclusions may only apply to Portugal and its unique circumstances, such as its history of disproportionately high rates of heroin use. However, it is safe to say that claims by drug legalization advocates regarding the impact of Portugal’s drug policy exceed the existing scientific basis.”
“Drug Decriminalization in Portugal: Challenges and Limitations.” Office of National Drug Control Policy. National Archives and Records Administration. Accessed May 5, 2020. https://obamawhitehouse.archives.gov/ondcp/ondcp-fact-sheets/drug-decriminalization-in-portugal-challenges-and-limitations.