International migration has been motivated by economic considerations throughout history. In recent times migration for resettlement, labour migration, and flows of undocumented migrants have been associated with significant economic disparities between sending and receiving countries. Although the forces giving rise to the movement of refugees are often non-economic in nature, the presence of refugees has economic repercussions.

During the past 50 years, the two main destinations of labour migration have been the industrialized countries of Western Europe and the oil- producing countries of the Middle East. Migration was promoted by the Governments of receiving countries in both regions to satisfy the labour needs of their growing economies. The labour- importing countries of Western Europe and the Middle East have at different times experienced a period of expansion followed by a recession. Inflows of foreign labour served to fuel or maintain the expansion, but during the recessions some migrants departed, often as a result of measures taken by the receiving country, while others remained.

Labour migration to Western Europe was officially stopped around 1974, but migration to the Middle East increased rapidly at that time and peaked by about 1983. The discontinuation of labour immigration in Western Europe did not, however, stop migration completely. The adoption of policies favouring family reunion fuelled the continued growth of the foreign population in most receiving countries, except Switzerland. By 1982 there were nearly 13.2 million foreign residents estimated to be in the main receiving countries of Western Europe (Federal Republic of Germany, France, the United Kingdom of Great Britain and Northern Ireland, Switzerland, Belgium, the Netherlands, Sweden, Austria, and Luxembourg). By 1980, there were approximately 2.8 million foreign workers in the Middle East. Lack of reliable data makes that estimate a tentative one and precludes definite assertions about the evolution of migration during the early 1980s. Data on work permits issued by the United Arab Emirates, Bahrain, Kuwait, and Qatar indicate a decline as of 1983 and 1984. Although the inflow of migrant workers may be declining, an increasing proportion of them appear to be remaining after the completion of their initial contracts. Thus, as in Europe, the total foreign population in the Middle East may not decline even if the inflow of foreign labour is stopped.

In addition to the benefits accruing to the workers themselves, employers in the receiving countries during the period of expansion benefited from the importation of labour that tended to prevent sharp rises in domestic wages. Unemployment in the receiving countries was mitigated, however, by the departure of foreign workers in periods of contraction. Their return tended to reduce wages, increase unemployment and underemployment, and reduce foreign exchange earnings in their home countries.

The selectivity of migration has had undesirable effects in some sending countries whose emigrants have tended to be better educated and to possess higher skills than the average population. In those countries the depletion of the pool of local skilled labour has been a serious impediment to the expansion of modern economic activities. Opportunities for migration have encouraged some people in other countries to invest in their own education. Although returning migrants tend to bring back some of their foreign earnings, other benefits that might be expected from the return of migrants have not always materialized. Migrants have generally experienced negligible occupational upgrading while abroad, and those choosing to return seem to be negatively selected in terms of skills, age, or health status. In addition, some sending countries often lack the open and flexible socio-economic environment that stimulates the success of the innovating individual.

Among the factors responsible for immigration to the United States, satisfying the need of the economy for workers plays only a minor role. It is interesting to note, nonetheless, that the number of foreign- born persons living in the United States in 1980, 14.1 million, is of the order of magnitude of the number of foreigners in the former labour- importing countries of Europe. This foreign-born population in the United States included the survivors of permanent immigrants (about 9.2 million from 1956 to 1980), a small number of temporary workers and trainees (approximately 300,000 of whom were admitted since 1971), and an estimated 2 million undocumented immigrants. From 1981 to 1987, the United States admitted 4 million permanent immigrants and about 500,000 temporary workers and trainees. In addition, some 1.7 million people have applied for legal residential status under an amnesty programmeme for certain groups of undocumented immigrants.

Predicting likely trends in international migration is a precarious task, because it is greatly affected by unpredictable political, economic, and social circumstances in both countries of origin and destination. International migration can change dramatically, even reversing direction, in a comparatively short time. For some countries, net migration is relatively small. Consequently, in the preparation of estimates and projections at the national level, no migration was assumed. For those countries that have a long history of international migration, a simple constant net migration flow was assumed. For other countries it was generally assumed that the current migration flows would decline and reach zero at around the year 2000. For countries in which migration has been of a temporary nature resulting from either civil conflicts, sudden change in the national economy, or specific governmental policies, migration was assumed only for the period from 1985 to 1990.

Refugee movements form a most dramatic type of international migration. Conventional refugees are those who have crossed an international border to avoid being persecuted or to escape war-like conditions in their home countries. De facto refugees include those who have left their country under normal departure procedures but are prohibited from returning home without risking their lives owing to intervening events there.

The current global refugee population is estimated to be about 12 million. Some four-fifths are found in developing countries, including somewhat less than one third in Africa. During the past few years some Western countries have tended to restrict the granting of asylum. There is reason to believe that the proportion of refugees accommodated in the developing countries will be increased in coming years, even though developing countries have experienced serious socio-economic problems with hosting large refugee populations.

Approximately half the global refugee population is currently assisted through official schemes. Examples are reception centres, holding centres, camps, or designated land settlements and villages. The remainder have found a place to stay on their own, sometimes illegally or in consultation with local people and authorities, often in areas bordering their home countries. In addition to relief supplies, these schemes to aid refugees often include social infrastructure, such as schools and health centres, to which local people may also have access. But distribution of food and other relief items is limited to refugees, even in areas with groups of destitute local people. With the exception of land settlements where refugees are given plots to cultivate, income- generating activities have been developed for only a small percentage of refugees in most official schemes. In some cases, refugees in official schemes do not receive their entitlements; distributions are irregular, and they must find supplementary sources of income. Thus they often provide labour and services for surrounding host populations. Barter systems involving the exchange of donated relief items for items of local production between refugees and their hosts have developed in some areas. A recent large-scale survey of the socio-economic conditions of refugees in Pakistan, host to about one fifth of the estimated global refugee population, found that new arrivals have less means at their disposal per household member than those who arrived earlier. They are also most frequently subject to irregular food distributions. Some refugees have experienced conflict with local citizens when seeking employment or agricultural land, or when collecting firewood and other natural resources. Similar friction has been reported in other countries as well.

In areas with relatively abundant resources and a buoyant local economy, refugees are often well received. They are willing to engage in menial tasks despised by others, including unskilled manual work for local farmers. Refugees will search for vacant land and develop their own agriculture, or supply unskilled and semi-skilled labour to local building contractors and manufacturers. Some take up crafts and trade and increase the varieties and quantity of locally available goods. But because more of the casual and unskilled work is undertaken by the refugees, their activities may indirectly worsen the conditions of some members of local vulnerable groups such as female heads of households, the disabled, and the elderly who all depend on this work for their incomes. Over time, friction between refugees and these groups may materialize, and some refugees or local destitute groups may leave the area. On balance, the refugee inflow contributes positively, however, to the general development of areas with adequate resources and economic growth.

In poorer areas, refugees are resented by many. As they flood the labour market, wages drop for casual labour and even for semi- skilled and skilled jobs. Local prices for food, fuel, medical supplies, and commodities often rise. Refugees may collect firewood for fuel in neighbouring areas and further afield, contribute to deforestation in some areas, and impede the access of local people to common property resources. Although employers benefit from the ready labour supply provided by refugees, many workers and destitute groups do not. The resentment may lead to violence, with the result that a part of the refugee population may be relocated and have to start again in a new setting.

It is impossible, of course, to predict whether the size of the world refugee population will tend to increase over time because of the unpredictability of conflicts that give rise to them. Nonetheless, in countries that currently host large numbers of refugees, budgetary provisions will have to be made to provide assistance during the foreseeable future.