Despite the political problems of the last six years with the break up of fede? ration, the unila er declaration independence, and the application of sanctions, Rhodesia's economy has shown a remarkable resilience and has not suffered as badly as many economists had predicted. This is due in part to the country's diversified economic basis and help received from South Africa, Portugal and elsewhere. Rhodesia is comparatively well endowed with a large variety of minerals, whose export value in 1964 was nearly ?27 million, consisting of gold worth ?7-2 million, asbestos ?6*8 million, copper ?4-1 million, coal ?3-4 million, chromite ?2-2 million, tin ? -65 million, iron ore ? -58 million, and other minerals. Reserves of coal and iron ore are large with a production of over 3 million tons of coal and a million tons of iron ore in 1964. Hydroelectricity generated from Kariba will be able to supply all of Rhodesia's power needs for years to come. Industrial development has been rapid since 1938 when net output was worth ?2*3 million, compared to a net output worth ?22 million in 1963, while numbers employed have also increased from 17,500 to 82,400 during the period 1938-63. Manufacturing is now the largest single sector in the Rhodesian economy with 18 per cent of the gross domestic product, compared to commercial agriculture with 15 per cent of the G.D.P. However, commercial agriculture was the largest employer of African labour with 44 per cent of a total African labour force of 622,000. Rhodesian agriculture is divided into two distinct sectors, the cash and the subsis? tence sectors. The commercial sector is market-orientated and consists largely of Euro? pean farmers operating on a large scale, while the subsistence sector consists almost entirely of African peasant cultivators operating on a small scale and with little (market emphasis. Over 90 per cent of the African working population are engaged in farm? ing, and there are nearly half a million African subsistence farmers compared to only 6200 farms in the commercial sector, most of them owned by Europeans, but includ? ing an increasing number of Africans. Agriculture is, therefore, of paramount importance to the Rhodesian economy and will continue to play a major role for many years to come. However, despite the apparent vigour of the economy there are some disquieting features. The contribution of subsistence agriculture to the national economy is small as yet, with only 67 per cent of the G.D.P. in 1964, and most African farmers are inefficient with a low standard of living. Determined efforts are being made by the Rhodesian government to improve agricultural productivity by such means as cooperative marketing schemes, the African Master Farmers' Scheme, soil conservation programme, pasture management, the upgrading of cattle and the introduction of new and better varieties of crops. The African population is expanding at a rate of 3 xz per cent per annum, having in? creased from about half a million in 1901 to 3 lz million in 1961. Increasing numbers of Africans are migrating to Bulawayo and Salisbury, and the latter city, which had only 33,000 people in 1933, increased rapidly to over 300,000 by 1966. A major reason for this urban drift is the effect of the widening gap between urban and rural earnings. According to Professor Arthur Lewis another important reason is the in? fluence of accelerated schooling causing African primary school leavers to flock to the towns to seek work, as suitable employment is not available in the country (Lewis,