2.4 Migration

For purposes of describing the development of the population we need to have information not only on birth rate and mortality, but also on migration. Each year large numbers of people move from one place to another. This causes an increase in some local population numbers and a decrease in others. The main trend of migration has seen a growing concentration of people in large population centres. Only very few people have moved in the opposite direction. In Finland, migration has caused population numbers to increase in the south of the country. In the late 1960s, exceptionally large numbers migrated to Sweden.

Statistical measures describing migration are formed in the same way as those describing fertility and mortality: the numbers who have moved are compared to the total population and usually expressed per one thousand persons. However, migration is often represented by one single figure, which is known as net migration. This is obtained by deducting the number of those who have moved out of an area from the number of those who have moved into that same area. If out-migration exceeds in-migration, net migration is negative.

In 2007, the net migration figures for Helsinki and Enontekiö were as follows:

Helsinki
35,830 (in-migration) - 33,054 (out-migration) = 2,776 (net migration)

Enontekiö
94 (in-migration) - 121 (out-migration) = -27 (net migration)

The net migration figure is compared to the total population concerned. For example, net migration in Helsinki (2,776) is compared to the Helsinki population (568,531), which gives the negative net migration rate of 4.9 persons per one thousand population.

Using the same formula, the negative net migration rate for Enontekiö was -1.4 persons per one thousand population.

Net migration rates vary widely between different municipalities. Especially in smaller municipalities migration may show quite considerable random variation. In 2007, the lowest net migration rate in Finland was recorded for Lestijärvi, where a negative net migration of 37 persons translated into a negative rate of -40.9 persons per one thousand population; and the highest for Lemu, where a positive net migration of 82 persons meant a positive rate of 46.5 persons per one thousand population.