The United Nations Office on Drugs and Crime estimated that organized crime groups and criminals around the world made up to $2.1 Trillion in 2009. Based on that year’s GDP, the amount accounted for 3.6 percent of GDP.
The Havocscope Illicit Trade Value estimates the global black market to be $1.78 Trillion.
Source: Alex Plough, “New tactics needed in the war against dirty money,” Thomas Reuters Foundation, June 13, 2013.