Migration, Theory of

Theorists in a variety of disciplines have offered theoretical explanations for human migration. This article reviews the leading models that have been developed to theorize five facts of human migration: the structural forces that promote 'out-migration' from sending regions; the structural forces that attract 'in-migrants' to receiving societies; the motivations, goals, and aspirations of people who respond to these structural forces by becoming migrants; the social and economic structures that arise to connect areas of out- and in-migration; and the actions taken by states to influence the number and characteristics of immigrants. These models include neoclassical economics, the new economics of labor migration, segmented labor-market theory, social capital, cumulative causation, world-systems theory, and securitization theory.