World wheat trade is highly concentrated. Thirteen countries accounted for 95 percent of wheat exports and 18 countries accounted for more than 71 percent of imports during 1981-83. The United States is the dominant exporter with more than 44 percent of world exports during 1981-83, but that position of dominance is coming into increasing competition. The U.S. export share is projected to erode substantially over the years ahead. Eight major exporters in 1981-83 were importers in 1961-63. Similarly, there have been substantial changes on the importer side. The major importers, who accounted for 71 percent in 1981-83, accounted for only 25 percent of wheat imports in 1961-63. The USSR, a significant exporter in 1961-63, was the largest single importer in 1981-83, with more than 20 percent of wheat imports.