"The global illicit flow of goods, guns, people, and natural resources is estimated at approximately $650 billion. Though data is scarce and experts are constantly debating the relative merits and weaknesses of every new study, it is generally accepted that illicit drug trafficking and counterfeiting are the two most valuable markets. This report finds the illicit drug trade to be worth roughly $320 billion and counterfeiting $250 billion."

Source

Haken, Jeremy, "Transnational Crime In The Developing World," Global Financial Integrity (Washington, DC: Center for International Policy, February 2011), p. v.
http://www.gfintegrity.org/st…