The sweetener industry is divided into several segments, based on geography, the plant (beet, cane, or corn) from which the sweetener is obtained, and the functions performed by different producers. The production and marketing of sugar in the United States have been controlled by a quota system since 1934. This system, supported by the domestic sugar industry, has been administered so that U.S. sugar prices have usually been well above those in the world market. Individual sugar producers apparently have not had sufficient market power to affect the general level of prices over a long period of time. Producers of corn sirup and dextrose have benefited to some extent from the protection received by the sugar industry, since these products compete with sugar. Saccharin, the principal noncaloric sweetener, competes to some extent with sugar.