The Institute for Economic Development at Boston University                                                                    Research Review Spring 1999

The evidence on patterns of migration draws upon census data and several household surveys. Although most of the attention of economists has focused upon rural-urban migration, intra-rural migration is shown to be more common in many of the lower income countries, though much of this movement is between neighboring villages. As the portion of population remaining in rural areas dwindles at higher income levels, urban-urban migration increases and the contribution of rural-urban migration to urban population

The survey of recent literature indicates large gaps in our empirical evidence. Most attention has been directed toward the causes of internal migration. It is well established that employment opportunities play a major role, but very little information exists on the significance of networks, risk spreading, public amenities or violence. Less attention has been given to the consequences of migration: the evidence on whether migration promotes wage convergence between regions is found to be mixed and almost no evidence exists on convergence of unemployment; factors contributing to rural-urban earnings gaps and job search by migrants have begun to be studied and these findings are summarized; the contribution of migrants’ remittances to consumption smoothing remains contentious; and the causes of mega-city growth in the developing countries lacks empirical analysis though it has attracted some theoretical interest.