Migration

The relationship between the numbers of births and deaths (natural change) is not the only factor in population change. The balance between immigration and emigration (net migration) must also be taken into account. The relative contributions of natural change and net migration can vary both within a particular country and between countries.

Migration tends to be subject to distance-decay - the number of migrants declines as the distance between origin and destination increases. Refugees tend to move only short distances; economic migrants travel greater distances.

Migration is more volatile than fertility and mortality. It is affected by changing physical, economic, social, cultural and political circumstances. However, the wish to migrate may not be fulfilled if the constraints are too great. The desire to move within a country is generally inhibited only by economic and social factors. The desire to move to another country is usually constrained by political factors, such as immigration laws.

Internation migrants make up about 3% of the worlds population. Economic conditions, social and political tensions, and historical traditions can influence a nations level of migration. Net migration rates can mask offsetting trends such as immigration of unskilled workers and emigration of more educated residents. Redent net migration trends raise sime interesting issues. Patterns of international migration have been changing since the later 1980's. There have been increases in:

• attempts at illegal, economically motivated migration as a response to legal restrictions
• those seeking asylum
• migration between more developed countries, particulary between countries within the EU where restrictions have been removed to allow the free movement of labour
• short-term migration, as countries increasingly place limits on work permits. It is now common for more developed countries to limit the length of work permits, even for qualified migrants coming from other more developed countries
• movement in migrants between less developed countries, particulary to those where rapid economic development is taking place, for example the countries of the Perisan Gulf and the Asian economic growth areas of Singapore and Indonesia.

There has been a decline in:

• legal, life-long migration, particularly from less to more developed countries. Host countries provide fewer oppertunities for migrants because the number of available low-skilled jobs has dropped. Mnay host countries have also tightened entry requirements and introduced more rigorous monitoring at the point of entry.
• the number of people who migrate for life. Many newer migrants want to return home at some point. For example, a common feature of villages in Italy, Portugal and Greece is new housing built by returnees.
• the number of people migrating with the purpose of reuniting family members, as the amount of long-term family seperation reduces and many migrants eventually return home.

Refugees are defined by the UN as persons unable or unwilling to return to thier homeland for fear of persecution, based on reasons of race, religion, ethnicity or political opinion, or those who have been displaced forcibly by other factors.

By 2003, the UN estimated that there were over 22million refugees in the world. Many refugee movements are large-volume, non-selective and over short distances. They are often caused by war. Such migrations are often temporary - when the cause of the migration ends, the refugees return to thier former homes. At the end of the 20th century and beginning of the 21st, major movements have included:

• 2 million from Ethiopia, Sudan and Somalia as a result of famine and civil war
• 6 million from Mozambique as a result of famine, civil war and flooding
• 1 million Kurds from northern Iraq fleeing oppression
• 1 million Afgans into neighbouring Pakistan fleeing civil strife and war
• 100000 Tamils fleeing oppression and civil war in Sri Lanka
• 7000 residents of Montserrat fleeing a volcanic eruption in the Soufriere Hills.

One defintion of asylum is 'the formal application by a refugee to reside in a country when they arrive in that country'. The numbers seeking asylum have incsreased steadily in recent years as countries seek to curtail immigration. The prominence of asylum seeking has increased for the following reasons:

• pressure to migrate from the poorest states is increasing because of economic decline and political instability
• improved communications enable people to learn more about potential destinations
• in real terms, the cost of transport has declined
• more gangs of traffickers are preying on would be migrants and offering a passage to a new life.

It can be difficult to distinguish between those fleeing from threats to thier life and liberty and those seeking to escape poverty and improve thier quality of life.