The U.S. received a large inflow of net factor income from Americans working and investing abroad. Other countries reported GDP, because their GDPs were larger than their GNPs. They paid Americans to work and invest in their countries. The FRB St. Louis reports real GNP and real GDP in 1996 chain-weighted dollars. The FRB Dallas reports and graphs real GNP and real GDP in 1992 chain-weighted dollars.
Real output is an imperfect measure of an economy's real income.
First of all, it is constructed from estimated quarterly tax returns. Because households and corporations often get extensions to file their tax returns, the actual GNP or GDP for any given year is not known for two or three years. Second, because real output is constructed from tax returns, only reported transactions are included. Illegal transactions, cash and carry transactions, local transactions that are not part of organized markets, barter transactions, and homemade goods and services are not included. Fourth, positive externalities are not fully included.