Graphic: Greece's shadow economy is one-fifth of its GDP

Italy second among countries where shadow economies are well established

Some countries have much larger shadow economies than others. Greece’s shadow economy is worth over a fifth of its total output, and Italy’s isn’t far behind. 

A country’s shadow economy is the total value of transactions by businesses and individuals that occurs “off the books”. 

The World Economic Forum’s Global Agenda Council on Illicit Trade 2012-2014 estimated the global shadow economy to be worth $650 bn.