From 1945 to 1973, the Japanese economy maintained an annual growth rate of nearly 10 percent. Because the standards for measuring national income changed during this period, there is no continuous statistical series. However, when the existing data are linked and recalculated, Japan's real GNP shows an annual growth rate of 9.6 percent from 1946 to 1973.

The first decade of this high economic growth was a period of recovery from the economic dislocations brought about by Japan's defeat in World War II. During the war, Japan's maritime transport was cut off by the Allied powers, and it had been difficult to obtain raw materials. In effect, this blockade was continued by postwar restrictions that the American occupying forces imposed on foreign trade, and it was exacerbated by social and economic disorder. Real GNP per capita in 1946 declined to 55 percent of the 1934–6 level as a result, and it did not recover that level until 1953.

The tempo of Japan's postwar recovery from the wartime destruction appears rapid in comparison with that of the countries of Western Europe, because the postwar collapse in Japan was so great, but it actually took the prewar per capita GNP longer to recover in Japan than it did in Europe. In 1951 the per capita national income, based on the prevailing exchange rates, was one-twelfth that of the United States and two-fifths that of West Germany. But once the postwar recovery was complete, Japan maintained an extremely high rate of growth for more than fifteen years.