The role of local migration in African development

Surveys over several years in the Kagera region of Tanzania have shown that migration has a positive impact on people's living standards, even for those who remain in agriculture. On the other hand, there is evidence of migrants ending up in unfavourable social environments and perhaps even that the traditional home communities are protecting their livelihood and survival by setting up subtle exit barriers, in the form of norms, preventing migration of their most productive members. So, should migration be encouraged at all costs?