Paraguay has a market economy marked by a large informal sector. The informal sector features both reexport of imported consumer goods to neighboring countries as well as the activities of thousands of microenterprises and urban street vendors. Because of the importance of the informal sector, accurate economic measures are difficult to obtain. A large percentage of the population derives their living from agricultural activity, often on a subsistence basis. The formal economy grew by an average of about 3% annually in 1995-97; but GDP declined slightly in 1998, 1999, and 2000, rose slightly in 2001, only to fall again in 2002. On a per capita basis, real income has stagnated at 1980 levels. Most observers attribute Paraguay's poor economic performance to political uncertainty, corruption, lack of progress on structural reform, substantial internal and external debt, and deficient infrastructure.