Factors affecting change in the population of an area are births, deaths and migration. Migration is one of the most complex demographic variables.
Like deaths it can occur at any time. Migration can affect the growth of population directly, and by influencing fertility and mortality of the area of origin and destination. The measurement and analysis of migration are important in the preparation of population estimates and projections for a Region. Furthermore, it is of particular significance for manpower and Regional planning.
Mbeya Region is one of the Regions in the country that experience persistently positive net migration. Other Regions are Dar es Salaam, Shinyanga, Manyara, Arusha, Morogoro, Tanga,
Tabora, Rukwa and Kagera. There are several reasons that cause positive net migration in these Regions. Among them are strong industrial and commercial base, large scale plantations, and availability of social services including school facilities, health infrastructure and looking for greener pastures.
The 1988 population census revels among many things that Mbeya Region had the forth largest positive net life time migration of 49,999. This means that the number of people who came to live in Mbeya Region were more than those left the Region.
In spite of the declining socio-economic performance and bad weather in recent years, the 2002 population census results reveals significant changes in migration pattern in the country with increase in the magnitude of net migration. Nevertheless Mbeya Region was seventh after Dar es Salaam (991,416), Shinyanga (384,546), Manyara (220,350), Tabora (106,945), Arusha (83,733) and Morogoro (75,939).