PICTURE: Zimbabwe Has The Biggest Shadow Economy In The World - Report

Zimbabwe has been placed top on the list of countries with the biggest shadow economies in the world. This is according to a 2015 report by the Global Economy which placed Zimbabwe on number one claiming the Zimbabwean economy is 67% informal.
Defining a shadow economy, Wikipedia said:
illicit economic activity existing alongside a country’s official economy, e.g. black market transactions and undeclared work.
From Africa, Gabon and Nigeria join Zimbabwe in the top 5 of the shadow economy rankings in the world. No other data is available on shadow economies since then. The IMF report on the subject was also published in 2015.
More: The Global Economy