Colonial external trade was generally depressed as the British Empire entered the war, having declined in value from the brief rearmament boom of 1937 by over 20 per cent by 1939 (Table 10.1). The African and Caribbean colonies experienced subdued trade conditions until 1943, although export earnings rose faster in Ceylon and Mauritius. In the last two years of the war trade values increased more rapidly, by 19 per cent overall and in the first full year of peace trade values rose by 25 per cent, as the post-war boom got under way. The volume of trade declined during the war in many cases. Tables 10.2 and 10.3 present details of the movement in volumes of major export and import commodities. West African exports of cocoa, palm kernels, palm oil and groundnuts were all below their 1938 volume levels in 1945, although there was some increase in tin ore and manganese (and iron ore from Sierra Leone). A similar situation obtained in the Caribbean where sugar, cocoa and bananas were below 1938 volume levels by 1945, but bauxite from British Guiana expanded rapidly. In East and Central Africa the volume of cotton and coffee exports declined though sisal increased slightly. Copper and zinc output from Northern Rhodesia, however, doubled. As regards the the eastern colonies not overrun by the Japanese, tea and sugar export volumes from Ceylon and Mauritius were lower in 1945 than in 1938 though were higher in some of the intervening years. With the fall of Malaya in 1942, Ceylon became Britain’s main source of rubber and the volume exported virtually doubled. Thus, except for strategic minerals and raw materials, for which special efforts were made, the physical quantities of commodities exported from the tropical colonies declined during the war. This was caused by low prices, diversion of labour, shortages of inputs such as fertilisers and machinery and inadequate shipping. Many colonial exports were subject to bulk purchase by Britain at rock bottom prices, which had a disincentive effect on producers. Where export volumes were increased in response to the war effort higher prices were paid and a higher priority for shipping given.