The U.S. Generalized System of Preferences (GSP) is a program of the U.S. government to promote economic growth in the developing world through trade mechanisms. The GSP provides preferential duty-free treatment for 3,400 products from 132 countries, of which 44 are least-developed countries. The GSP went into effect on 1 January 1976 under authorization of the Trade Act of 1974 (19 USC 2641 et seq.) for a ten-year period. The GSP has been renewed continually, and in 2006 was renewed until 31 December 2008.