The divergence of private from social costs in rural-urban migration: a case study of Nairobi, Kenya

In Developing Economies the level of urban wages tends to induce more people to seek employment in the towns than can be employed at this wage level. The existence of these urban unemployed causes the private costs of migration to diverge from the social costs. The individual rural resident decides to remain or migrate on the basis of perceived private costs of migration. The effect of a decision to migrate on the economy is the social cost of migration. In our study we consider the determinants of different levels of private and social costs associated with different stocks of urban unemployed. In addition, utilizing survey data on Nairobi, Kenya, an attempt is made to quantify the major private and social costs of migration to determine whether they diverge significantly. On the basis of these estimates some policy options for limiting urban unemployment caused by urban in-migration are considered. In a survey of research on migration in Africa, Derek Byerlee suggests that it is likely that the private and social returns to migration diverge and he calls for research to determine the magnitude of this divergence (1, p.16), Our study is a partial response to this request. Data collected in a 1968 survey (see Appendix) are used to measure the divergence of private from social costs of in-migration into Nairobi during the period 1964- to 1968. Such a limited study may arouse criticism from those who would wish a more balanced approach dealing with both costs and benefits. We would like to indicate at the outset that we are in no way implying that the costs outweigh the benefits of migration. We conclude with a discussion of policy issues which indicates ways of modifying the costs without jeopardizing the benefits.