This chapter identifies some of the main labour supply implications of the changing age structure of the population and migration trends within the United Kingdom and western Europe in the 1990s, placing them in the context of likely changes in the character of labour demand over the same period. As the populations of many western European countries remain relatively stable in size, increasing attention has been focused on two aspects of population change: first, changes in age structure; and secondly, changes in spatial distribution. The foremost features of the changing age structure of the population focused on in this chapter are the increase in the number of elderly people, and the decline in the number of school-leavers. With regard to changes in spatial distribution, the emphasis is on macro-scale trends; notably, the differential growth and decline of urban and rural areas, and of core and peripheral regions. These changes in age structure and spatial distribution have implications for the size and composition of the population of working age in different areas.