According to research by Rafael La Porta of Tuck School of Business at Dartmouth and Andrei Shleifer of Harvard University, in developing countries, the average firm in the informal sector, or underground economy, employs 4 workers as opposed to 126 workers employed by the average firm in the formal sector. What is the informal sector, or underground economy? A. This is the part of the economy where production is heavily taxed by the government. B. This is the part of the economy characterized by the pollution and other negative externalities its production creates. C. The informal sector, or underground economy, is when production occurs in other countries. D. The informal sector is the sector of the economy where production is concealed from the government..