MIGRATION THEORIES AND EVIDENCE: AN ASSESSMENT

Abstract. This paper presents a critical survey of theories of migration, their welfare and policy implications and their empirical relevance. We also develop some extensions to the theory beginning with the Harris and Todaro (HT) model. In particular, the HT model is extended to examine risk averse behaviour within families where the migration of members of families serves to diversify risk. The welfare implications of the individual migration decision and government intervention in the form of employment subsidies are examined. Recent evidence on international migration is presented. It is shown that migration does not flow automatically in response to wage differentials. Characteristics of migrants and the process of self-selection are found to be important determinants of the rate of migration.