We establish five facts about the informal economy in developing countries. First, it is huge, reaching about half of the total in the poorest countries. Second, it has extremely low productivity compared to the formal economy: informal firms are typically small, inefficient, and run by poorly...

In developing countries, informal firms (those that are not registered with the government) account for about half of all economic activity. We consider three broad views of the role of such firms in economic development. According to the romantic view, these firms would become the engine of...