From an article on VoxEU last week:
Shadow economies all around the world: Model-based estimates
Ceyhun Elgin & Oguz OztunaliEven though informality is a widespread phenomenon and poses serious social, economic, cultural, and political challenges across the world, many issues about its nature and consequences still remain largely under-explored or unresolved. For example, the evidence presented in the existing literature has failed to generate a consensus among researchers around the measurement of the informal sector…