WHY PEOPLE MOVE Rural-urban migration is a human response to the geography of uneven development. Excluding involuntary relocation by refugees, most people move for economic reasons' (Table 23.1). Several models have been proposed to account for migra tion. The classical economic models of the 1960s saw migration as a response by individuals to place differences in job opportunities and wage rates Migration was viewed as a mechanism for eliminat- ing such differentials by matching labour supply and demand. and thereby contributing to national economic development, 2 A second. neo-classical economic perspective also represented migration as a process in which individuals make a rational eco- nomic choice based on the current or likely future benefits of a move. More recent interpretations, based on a political economy approach, focused attention on the structural forces underlying spatial variations in economic opportunity. This historical-structural perspective emphasises the importance of level of development in determining the scale and form of migration, and stresses that the significance of the various development-related factors underlying migration differs between countries and over time.4 This thesis is linked directly to the incorporation of Third World countries into the global economy. The urban bias inherent in the colonial capitalist devel opment of the Third World introduced considerable differentiation into what had i en frequently quite egalitarian societies, with mostrople having access