INTERNATIONAL MIGRATION

The history of international migration over the last five centuries can be divided into four periods.

The Four Periods of Migration

During the mercantile period, from 1500 to 1800, the dominant flows were out of Europe and stemmed from processes of colonization and economic growth under mercantile capitalism. Over the course of 300 years, Europeans came to inhabit large portions of the Americas and some portions of Africa and Asia in numbers that were modest but sufficient to establish dominion.

During that period European emigrants fell into three classes: a relatively large number of agrarian settlers, a smaller number of administrators and artisans, and an even smaller number of plantation entrepreneurs. Although the number of Europeans involved in plantation agriculture was low, this sector had a profound impact on the size and composition of populations in the Americas, since the most important source of plantation labor was African slaves, some 10 million of whom were forcibly exported to the New World before the closing of the slave trade in the early 1800s.

The industrial period began early in the nineteenth century with the economic development of Europe and the spread of industrialism to former colonies in the New World. From 1800 to 1929, 48 million people left Europe in search of new lives in the Americas and the area now known as Oceania. (Many of them eventually returned; thus, net migration was appreciably smaller.) Among those emigrants 85 percent went to five destinations–the United States, Canada, Argentina, Australia, and New Zealand–with the United States receiving 60 percent. Key sending countries were Great Britain, Italy, Norway, Portugal, Spain, and Sweden, all of which exported a significant share of their population increase during the period of industrialization.

Mass emigration from Europe was brought to a halt in 1914 by the outbreak of World War I and definitively ended by the economic crash of 1929. The years 1930–1960 were a period of limited international migration. The Great Depression stopped virtually all such population movement during the 1930s, and in the 1940s international migration was checked by World War II. What mobility there was largely involved displaced persons and was mostly unrelated to the rhythms of economic growth and development. This pattern persisted well into the 1950s.

The period of postindustrial migration began around 1960 and constituted a sharp break with the past. Rather than being dominated by outflows from Europe to a handful of former colonies, international migration became a truly global phenomenon as the number of migrants expanded and the sources of supply shifted from Europe to the developing countries. Before 1930, 85 percent of all international migrants originated in Europe. Since 1960, 85 percent have come from Latin America, the Caribbean, Asia, and Africa. The variety of destination countries has grown to encompass all developed countries, including all the countries of the European Union, the oil-exporting countries of the Persian Gulf, Canada, the United States, Australia, Japan, and the Asian "tigers" of Singapore, South Korea, Hong Kong, and Malaysia. By 2000 a total of around 175 million persons were living outside their countries of birth, 45 percent in developed countries and 55 percent in developing countries.

Data Collection

The study of international migration is complicated by serious data problems. The definition of an "immigrant" varies from country to country and is bound up in legal codes, politics, and sometimes xenophobia. The collection of data on international entries and exits is sporadic and incomplete and is the responsibility of different agencies in different countries. Although data on numbers and characteristics of the foreign-born, or of "foreigners" in some other sense, are generally available from national statistical offices, standards of enumeration and definitions of who is included vary across countries.

Estimates of net international migration flows for major sending and receiving countries for which reasonably good quality data exist–the English-speaking traditional immigration countries and countries in Western Europe–are presented in Table 1 for periods somewhat different from those referred to above.

The United Nations Population Division has developed a set of standards for the classification of international migrants and publishes a regular series of reports on trends and patterns based on its reworking of national statistical data. According to these data, at the turn of the twenty-first century roughly a third of all international migrants were in Asia, a quarter were in North America and another quarter were in Europe, 13 percent were in Latin America and the Caribbean, and 4 percent were in Oceania. International migrants amounted to around 2.4 percent of the global population. The highest rates of out-migration were in Latin America, the Caribbean, the Pacific Islands, Southeast Asia, and South Central Asia. The highest rates of in-migration

TABLE 1

were in Australia—New Zealand, North America, Western Europe, and Western Asia (principally the Persian Gulf states). As a percentage of all residents, foreigners constitute 18 percent of the population in Oceania, 10 percent in North America, 4 percent in Europe, 3 percent in Africa, 2 percent in Latin America, and 1 percent in Asia.

Categories of International Migration

International migrants fall into four basic categories, depending on whether they leave voluntarily or involuntarily and whether they are well or poorly endowed with human capital. Involuntary migrants who lack skills and education are classified as refugees. Their out-migration is prompted directly or indirectly by persecution, threat of violence, or extreme deprivation and typically is directed toward a neighboring state. Involuntary migrants with significant human capital generally travel to nonadjacent states as asylum seekers; their departure is motivated by a fear of violence or persecution. Because of their education and in some cases their financial resources, they are better placed to gain entry to liberal, developed nations and to pursue claims for asylum. Voluntary migrants who lack human capital generally are classified as labor migrants. Their movement is motivated by economic aspirations, and so the flow is from less to more developed nations. Skilled immigrants carry significant amounts of human capital, and their migration decisions reflect the desire to maximize returns to their investments in skills, training, and education.

Just as markets for financial capital have globalized in recent years, so have markets for human capital. Although flows of human capital are predominantly from less to more developed countries, there is also significant mobility of skilled workers among the developed countries and among developing countries, as well as from developed to developing regions.

Only about 10 percent of the world's international migrants are refugees. Most refugee movement occurs among developing countries. Refugee migration tends to be localized and generally stems from civil conflicts within nations or the disintegration of a state. Although Africa contains only 13 percent of the world's people, it has a third of its refugees, mainly in sub-Saharan countries with weak and divided state structures inherited from colonial regimes. Another 36 percent of all refugees reside in Asia, mainly in the Middle East, Pakistan, and Southeast Asia. Finally, 25 percent are in Europe, principally in the former Yugoslavia and Soviet Union. Precise information on refugees is difficult to obtain; what little exists is tabulated by the United Nations High Commissioner for Refugees. There is little theoretical basis for predicting future trends.

Of the remaining international migrants, nearly 90 percent are workers (and their families) who left their countries of origin for economic reasons. They are predominantly unskilled.

Theories of International Migration

Theoretical work has sought to explain the movement of economic migrants in terms of (1) the structural forces that promote emigration, (2) the structural forces in destination countries that attract migrants, (3) the motivations, goals, and aspirations of those who respond to macrostructural forces by becoming international migrants, (4) the social and economic structures that connect areas of out-and in-migration, and (5) the responses of specific states to the resulting flows of people.

The frameworks that different analysts have drawn on are neoclassical economics, the new economics of labor migration, segmented labor market theory, world systems theory, social capital theory, and the theory of cumulative causation. World systems theory gives an account of the structural forces that promote out-migration from developing countries. Together, world systems theory, segmented labor market theory, and neoclassical economics explain why developed countries attract immigrants. Social capital theory and world systems theory explain how structural links emerge to connect areas of origin and areas of destination. Neoclassical economics and the new economics of labor migration deal with the motivations of the people who become international migrants in response to these forces. The theory of cumulative causation describes how international migration promotes changes in personal motivations and socioeconomic structures to give immigration a self-perpetuating, dynamic character. Finally, recent contributions to political economy offer a basic framework for understanding the role of state policy in determining the size and composition of international flows.

A Synthesis of Theoretical Approaches

Integrating the various theories in light of the empirical evidence yields the following synthetic account. Contemporary international migration originates in the social, economic, political, and cultural transformations that accompany the penetration of markets into nonmarket or premarket societies (as hypothesized under world systems theory). In the context of a globalizing economy, the entry of markets and capital-intensive production methods into peripheral areas disrupts existing social and economic arrangements and brings about the displacement of people from their customary livelihoods, creating a mobile population of workers who actively search for new ways of earning income, managing risk, and acquiring capital.

One means by which these people seek to assure their economic well-being is by selling their labor. Because wages are higher in urban than in rural areas, much of this process of labor commodification is expressed in the form of rural—urban migration. Such movement occurs even when the probability of obtaining an urban job is low, because when multiplied by high urban wages, the low employment probabilities yield expected incomes above those in rural areas. Wages are even higher, of course, in developed countries overseas, and the larger size of these wage differentials inevitably prompts some people to seek work abroad, often in geographically distant countries.

International wage differentials are not the only factor motivating people to migrate, however. Many households struggling to cope with the jarring transformations of economic development and market creation use international migration as a means of managing risk and overcoming barriers to capital and credit (considerations treated in the so-called new economics of labor migration).

In developing countries, markets (or government substitutes) for insurance, capital, credit, and old age security are poorly developed or nonexistent. Households turn to international migration to compensate for these market failures. By sending members abroad to work, households diversify their labor portfolios to control the risks stemming from unemployment, crop failure, and price uncertainty. Work abroad may also permit households more successfully to accumulate cash for large consumer purchases or productive investments or to build up savings for retirement. Whereas the rational actor posited by neoclassical economics takes advantage of a geographic disequilibrium in labor markets to move abroad permanently to achieve higher lifetime earnings, the rational actor assumed by the new economics of labor migration seeks to cope with market failure by moving abroad temporarily and repatriating earnings in the form of regular remittances or lump-sum transfers.

Whereas the early phases of economic development promote emigration, postindustrial transformations in high-income countries create a bifurcation of labor markets. Jobs in the primary labor market provide steady work and high pay for native workers, but those in the secondary labor market offer low pay, little stability, and few opportunities, thus repelling native residents and generating a structural demand for immigrant workers (treated by segmented labor market theory). This process of labor market bifurcation is most evident in global cities, where a concentration of managerial, administrative, and technical expertise leads to a concentration of wealth and a strong ancillary demand for low-wage services (as described in world systems theory). Unable to attract native workers for such service jobs, employers turn to immigrants and initiate immigrant flows directly through formal recruitment (segmented labor market theory).

Although instrumental in initiating immigration, recruitment becomes less important over time because the processes of economic globalization that create mobile populations in developing regions also generate a demand for their services in global cities and create links of transportation, communication, politics, and culture that make the international movement of people increasingly cheap and easy (world systems theory). Immigration also is promoted by foreign policies and military actions taken by core nations to maintain international security, protect foreign investments, and guarantee access to raw materials; these entanglements create links and obligations that generate ancillary flows of refugees and military dependents.

Once an immigration stream begins, it displays a strong tendency to continue through the growth and elaboration of migrant networks (social capital theory). The concentration of immigrants in certain destination areas creates a "family and friends" effect, which channels later cohorts of immigrants to the same places and facilitates their arrival and initial settlement. If enough migrants arrive under the right conditions, an enclave economy may form that further augments the specialized demand for immigrant workers (segmented labor market theory).

The spread of migratory behavior within sending communities sets off ancillary structural changes, shifting distributions of income and land and modifying local cultures in ways that promote additional international movement. Over time the process of network expansion tends to become self-perpetuating because each act of migration causes social and economic changes that promote additional international movement (theory of cumulative causation). Receiving countries may implement restrictive policies to counter rising tides of immigrants, but those measures create a lucrative niche into which enterprising agents, contractors, and other middlemen move to create migrant-supporting institutions, providing migrants with another infrastructure capable of supporting and sustaining international movement (social capital theory).

During the initial phases of emigration from any sending country the effects of capital penetration, market failure, social network expansion, and cumulative causation dominate in determining the international flows, but as the level of out-migration reaches high levels and the costs and risks of international movement drop, movement is determined increasingly by international wage differentials (neoclassical economics) and labor demand (segmented labor market theory). As economic growth occurs in sending regions, international wage gaps gradually diminish and well-functioning markets for capital, credit, and insurance come into existence, progressively lowering the incentives for emigration. If these trends continue, a country ultimately becomes integrated into the international economy as a developed, capitalist country, at which point it undergoes a migration transition. Massive net out-migration tails off, and the country itself is seen as an immigration destination; it becomes both a sender and a receiver of migrants.

These theoretical considerations go far toward explaining the initiation and perpetuation of international migration. The considerable regional variation in actual migration patterns stems from the fact that all national governments intervene in these flows to influence their size and composition. Sending countries, despite frequently voiced worries about the loss of human capital ("brain drain"), on balance have a strong interest in encouraging international migration as a means of acquiring capital, securing foreign exchange, relieving unemployment, and building skills. At the same time, however, migrant-receiving countries may be increasingly selective in their migrant intake or pursue more restrictive immigration policies.

Immigration and State Capacity

Globalization and technological change have combined to increase income inequality and unemployment in the world and have served to increase both the absolute and relative numbers of people seeking to enter the developed countries as immigrants. This process gives rise to more restrictive policies in the developed world. However, the ability of states to regulate and control the volume and composition of immigration is constrained by a variety of factors. Globalization itself limits the power of nation-states to control transnational movements of labor as well as those of capital, goods, and information. Similarly, the emergence of an international regime protecting human rights constrains the ability of governments and political leaders to respond to the racial and ethnic concerns of voters or to impose harshly restrictive measures on immigrants or their dependents. These constraints are particularly salient in nations with well-established constitutional protections for individual rights and strong, independent judiciaries.

Ultimately, the ability of immigrant-receiving states to impose restrictive immigration policies successfully depends on five main factors: the size of the potential flow, the degree of centralized power and relative efficiency of the national bureaucracy, the extent to which individual rights are constitutionally protected, the relative strength and independence of the judiciary, and the existence and strength of a historical tradition of immigration. The interplay of these factors determines a state's efficacy in restricting immigration.

Efficacy can be seen as a point on a continuum. At one extreme are countries, such as the Gulf states, which counter a moderate demand for entry with powerful centralized bureaucracies, few constitutional protections for individual rights, weak and dependent judiciaries, and no historical traditions of immigration. At the other extreme are countries such as the United States, which face a strong demand for entry with relatively weak and decentralized bureaucracies, strong constitutional protections for individual rights (including those of foreigners), a strong and independent judiciary, and a long historical tradition of immigration.

It is unclear how successful countries can expect to be in controlling immigration over the next century. Scattered evidence suggests that undocumented immigration is not unknown even in the Gulf states and is growing throughout Europe and Asia. In the United States both legal and illegal immigration continue to expand, and there is little evidence that the restrictive measures imposed so far have had much of an effect. U.S. policies have been more successful as symbolic political gestures, signaling to anxious citizens and workers that their concerns are being addressed while marginalizing immigrants socially and geographically to make them less visible. What remains to be seen is whether the majority of countries, situated at points on the continuum somewhere between the United States and the Gulf countries, will be able to regulate and control immigration over the next century.