In Scotland there is considerable interest, both official and popular, in the level and composition of net outmigration. Three new sources of migration data which have become available in recent years provide the basic data for this study: the migration tables in the 1966 sample census, the centralized data on the movements of doctors' patients within the United Kingdom, and the International Passenger Survey. Net out-migration from Scotland in the I96os has been greater to overseas countries than to the rest of the United Kingdom, and has been related closely to external factors of labour demand and to the extent of past migration; Canada has been the dominant destination. The pattern of migration between the regions of Scotland and the regions of England and Wales is controlled above all by relative distance and relative economic opportunities. IN ENGLAND AND WALES much of the current popular interest in population migration focuses on the immigration of coloured people. In Scotland, where such immigration and its associated problems are very slight, the concern is much more with the level of net out-migration to the rest of the United Kingdom and particularly to overseas countries. The need to stem this outflow is one of the main platforms of the active Scottish National Party, and the first chapter of the important White Paper, The Scottish Economy, 1965-70, a Planfor Expansion, is devoted almost entirely to a review of Scottish migration trends. This White Paper set out the Government's plans for the expansion of the Scottish economy to about I970, within the framework of the now-outmoded National Plan, and one of the stated main objectives was to halve the annual net out-migration from Scotland. Migration has traditionally been regarded as a means of narrowing inter-regional economic differences, particularly in the level of unemployment, but it is now being accepted that, within advanced economies, where the market orientation of service and manufacturing industries becomes a dominant locational consideration, it may actually accentuate these differences, owing largely to the inter-dependence between supply of and demand for labour. Thus within Scotland the level of net out-migration is being regarded with concern, for fear that, without positive remedial action, it might become a self-perpetuating process, as it helps to maintain those inter-regional and even international differences of which it is a function. Fortunately the growing interest in migration trends has been paralleled by a growing availability of basic migration data, and it is the purpose of this paper to examine the pattern of recent migration to and from Scotland in relation to three sources of data which have only become available in recent years. All three permit a study of gross as well as net movements and have the advantage of covering the whole population (although often on a sample basis) as opposed to some of the sources which have been used extensively in the past (for example, Ministry of Labour data on the movement of insured employees). Census Migration Tables In both Scotland and England & Wales the 1961 Census was the first to include a direct question on migration. It asked for a person's usual address on 23 April 1960, if it differed from