Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 156
BEYOND SIX BILLION: Forecasting the World's Population 6 International Migration International migration, the third force in population change, has no direct effect at the global level but can have substantial impact on specific countries. Immigration into the traditional countries of immigration has been a powerful demographic force, as attested by the history of these countries: the United States and Canada, Australia and New Zealand, and Brazil and Argentina. Immigrants have reshaped the demography of the Persian Gulf states in recent decades. Emigration has affected other countries, contributing to slowing population growth, especially in small, resource-limited island nations. Sudden mass emigration as a result of unpredictable economic or political crises is also a major reason for error in projecting population. The projections we examine generally do not treat immigrants and emigrants separately, relying instead on estimates and projections of net international migration. Net migration, however, is not the typical focus of migration research, which usually concerns itself with patterns and causes of either immigration or emigration separately. This chapter necessarily reflects the research available but does attempt to draw implications for net migration. Unlike fertility and mortality, which are in transition worldwide from high to low levels in a long historical process, international migration shows no global decrease. The stock of foreign-born population ranged between 2.1 and 2.3 percent worldwide over the years from 1965 to 1990, which implies that actual numbers of migrants have risen as populations have grown. The trend in numbers, therefore, is upward, although the exact dimensions are uncertain.
OCR for page 157
BEYOND SIX BILLION: Forecasting the World's Population International migration is the most complex of the population growth processes to project. To make a start, we review current trends in international migration and the theories that attempt to explain them. Drawing implications from this discussion, we consider how migration is projected and how projections might be improved. CURRENT LEVELS AND TRENDS In 1965, the world's stock of international migrants—those born in one country but resident in another—totaled roughly 75 million.1 By 1990, their numbers had risen to nearly 120 million. In just the 5 years between 1985 and 1990, the total stock of migrants increased by 15 million, or 2.6 percent annually, a rate of increase higher than the annual rate of natural increase in the population (Table 6-1). Net flows of migrants are nevertheless small for most countries. For the period 1990-1995, U.N. (1999) data show that half of all countries gained or lost less than 0.2 percent of population annually through migration. These low flows have generally held at least since 1970. In contrast, migration flows have been substantial in 10-15 percent of countries, which for some years in the period since 1970 either gained or lost 1 percent of population or more annually through migration. Furthermore, absolute net flows are growing. Collectively, all the countries that gained net migrants over the 1950s and 1960s added about 2 million people a year to their populations. In the 1970s and 1980s, this annual gain rose to 2.5-3.7 million, and in 1990-1995, it reached 5.1 million. The early 1990s were arguably an exceptional period that followed the fall of the Berlin Wall and saw several severe refugee crises. The relationship between the stock of international migrants and net migration flows is complex and is not examined here. However, it should be noted that a rise in the stock of migrants in a population can occur even when net migration rates are zero or negative. The main reason for this is that net migration results from offsetting flows of immigrants and emigrants. If emigrants are predominantly native, their departure does not 1 These figures are based primarily on census data on the foreign-born in each country, though, for some countries that do not collect data by birthplace, data by country of nationality are used instead. In a few countries, the numbers of foreign-born may be adjusted to conform to a national definition of international migration. For instance, the United States excludes those born abroad to American parents, who have a right to U.S. citizenship. The estimates generally reflect international political boundaries as of 1990. Thus, the former Soviet Union and the former Yugoslavia are treated as units, and figures do not reflect the redefinition of nationals and international migrants occasioned by their breakup.
OCR for page 158
BEYOND SIX BILLION: Forecasting the World's Population TABLE 6-1 Foreign-born population by world region, 1965-1990 Foreign-born population (1000s) As percent of regional population Region 1965 1975 1985 1990 1965 1975 1985 1990 World 75,214 84,494 105,194 119,761 2.3 2.1 2.2 2.3 Developing regions 44,813 46,177 57,203 65,530 1.9 1.6 1.6 1.6 Industrial regions 30,401 38,317 47,991 54,231 3.1 3.5 4.1 4.5 Africa 7,952 11,178 12,527 15,631 2.5 2.7 2.3 2.5 Sub-Saharan Africa 6,936 10,099 10,308 13,649 2.9 3.2 2.5 2.8 North Africa 1,016 1,080 2,219 1,982 1.4 1.1 1.8 1.4 Continental Asiaa 31,429 29,662 38,731 43,018 1.7 1.3 1.4 1.4 West Asia 4,683 6,374 11,810 14,304 7.4 7.6 10.4 10.9 South-Central Asiab 18,610 15,565 19,243 20,782 2.8 1.9 1.8 1.8 China 266 305 331 346 0.0 0.0 0.0 0.0 Other East/SE Asia 7,870 7,419 7,347 7,586 1.9 1.5 1.2 1.2 Oceania 2,502 3,319 4,106 4,675 14.4 15.6 16.9 17.8
OCR for page 159
BEYOND SIX BILLION: Forecasting the World's Population Latin America/Caribbean 5,907 5,788 6,410 7,475 2.4 1.8 1.6 1.7 Central America 445 427 948 2,047 0.8 0.6 1.0 1.8 Caribbean 532 665 832 959 2.4 2.5 2.7 2.9 South America 4,930 4,695 4,629 4,469 3.0 2.2 1.8 1.5 Northern America 12,695 15,042 20,460 23,895 6.0 6.3 7.8 8.6 Europe/FSU 14,728 19,504 22,959 25,068 2.2 2.7 3.0 3.2 Western Europec 11,753 16,961 20,590 22,853 3.6 4.9 5.8 6.1 Eastern Europed 2,835 2,394 2,213 2,055 2.4 1.9 1.6 1.7 Former Soviet Union 140 148 156 159 0.1 0.1 0.1 0.1 aIncludes the Middle East. bExcludes successor states to the former Soviet Union. cAll of Europe except the countries of the former Communist bloc. dAlbania, Bulgaria, the former Czechoslovakia, the former German Democratic Republic, Hungary, Poland, Romania, and the former Yugoslavia. Source: Zlotnik (1998), which draws on the U.N. Population Division's electronic database entitled Trends in the Migrant Stock by Sex(Revision 4). Refugees are meant to be included.
OCR for page 160
BEYOND SIX BILLION: Forecasting the World's Population FIGURE 6-1 Percentage of regional populations who are migrants, and regional shares of world migrant stock, 1990. SOURCE: Data from Zlotnik (1998). reduce the foreign-born stock, which could still rise from entering immigrants. International migrants are unevenly distributed across world regions (Figure 6-1). By 1990, 45 percent of the stock of international migrants were resident in industrial countries and 55 percent in developing countries. The largest shares were in three regions: Asia, with 36 percent, and Northern America (the United States and Canada) and Europe and the former Soviet Union, with about 20 percent each. An examination of the ratio of migrants to the resident population produces a very different pattern of regional variation. Given Asia's large population, migrants were a smaller proportion of the regional population (1 percent) than elsewhere. The highest ratios of migrant to resident populations were 18 percent in Oceania (mainly Australia and New Zealand), 9 percent in Northern America, and 6 percent in Western Europe. The factors promoting or hindering migration into and out of different regions and countries
OCR for page 161
BEYOND SIX BILLION: Forecasting the World's Population TABLE 6-2 Net migration per thousand by world region, 1985-1995 Region 1985-1990 1990-1995 Developing regions −0.5 −0.5 Industrial regions 1.6 1.9 Africa −0.5 −0.3 Sub-Saharan Africa −0.5 −0.2 North Africa −0.5 −0.9 Continental Asiaa −0.3 −0.4 West Asia 1.0 0.3 South-Central Asia −0.5 −0.8 East Asia 0.1 0.0 Southeast Asia −1.1 −0.6 Oceania 3.9 3.4 Australia/New Zealand 5.9 5.1 Pacific Islands −2.8 −1.8 Latin America/Caribbean −1.6 −1.2 Central America −4.2 −3.1 Caribbean −3.0 −2.4 South America −0.4 −0.4 Northern America 3.0 3.4 Europe 1.3 1.4 Western Europeb 1.9 1.9 Eastern Europec/Russia 0.5 0.9 aIncludes the Middle East. bIncludes what are designated, in the U.N. classification, as Northern, Southern, and Western Europe. cAs defined by the U.N., this grouping differs slightly from that used in the previous table (see United Nations, 1999). Note: These rates are not country averages but rates for entire regions from United Nations (1999). are so specific historically and culturally that each region must be examined individually.2 Africa had a stock of some 15.6 million migrants in 1990. For 1990-1995, the annual net migration rate for the continent as a whole was − 0.3 per thousand people (Table 6-2). In this period, countries losing population through migration were about equal in number to those gaining population through migration. Net migration figures may not adequately represent the true volume of international migration, given substantial movement across national boundaries, established during colonial times, that often cut across ethnic populations. 2 Portions of the following are drawn from Russell (1996).
OCR for page 162
BEYOND SIX BILLION: Forecasting the World's Population Africa as a whole (and Sub-Saharan Africa in particular) is distinctive for its production of refugees: nearly a third of the total of concern to the U.N. High Commissioner for Refugees3 at the beginning of 1997—about as many as in Asia, although the continental population is only a fifth of the Asian population. Crises and unexpected developments have been frequent, leading to sudden flows of migrants and steep changes in population growth rates. Around the world in the period 1970-1995, there were 23 instances in which population growth rates changed by more than 2.5 percentage points between successive 5-year periods. Half of these “demographic quakes” occurred in Africa, and large-scale migration was usually involved. These population movements have been volatile and sometimes accompanied by widespread suffering. Some of them have also been massive relative to national populations. In 1990-1995, the annual net migration rate reached −57.6 per thousand in Rwanda and −60.1 per thousand in Liberia, about 150 times the continent-wide rate. Much smaller but long-standing migration streams, mostly motivated by economic forces, have developed between particular Sub-Saharan African countries. These well-established streams include those from Burkina Faso, Mali, and Guinea to Côte d'Ivoire and those from Botswana, Lesotho, and Swaziland to South Africa. More recent streams include emigration from Côte d'Ivoire as a result of economic downturn (United Nations, 1998b:42) and the movement into South Africa of as many as 4 million illegal migrants from all parts of the continent.4 For North Africa, labor migration toward Europe has predominated. Within North Africa, Libya has been a regional pole of attraction from time to time, notably for Tunisians, although the sudden expulsion of Palestinian, Egyptian, and Sudanese workers during the early to mid-1990s reversed some of the flow. Asia had a migrant stock in 1990 of 43 million, and in the next 5 years, the continent as a whole experienced an annual net migration rate 3 The term “refugee” is defined by the 1951 U.N. Convention on the Status of Refugees and its 1967 Protocol to cover any person who “owing to well-founded fear of being persecuted for reasons of race, religion, nationality or political opinion, is outside the country of his nationality and is unable or . . . unwilling to avail himself of the protection of that country.” In some regions, this definition has been extended to include those forced to flee because of war, civil conflict, or other threats to peace and security. All refugees are “of concern ” to the U.N. High Commissioner for Refugees and are included in the statistics of that office, with the exception, for historical reasons, of Palestinians. Persons who flee other sudden-onset conditions, such as environmental disasters or famine, are not considered refugees but are included under the broader term “crisis migrants.” 4 Statement by Claude Scravesande, Director of Alien's Control, Home Affairs Department, reported in Migration News (1999:38).
OCR for page 163
BEYOND SIX BILLION: Forecasting the World's Population of −0.4 per thousand population. The numbers of countries losing and gaining migrants were almost equal, but if West Asia (with its oil producers) is excluded, losers outnumbered gainers by 3 to 2. Subregions on the continent, particularly South-Central and Southeast Asia, experienced greater than average net emigration. Over the span of several decades, Asia has contributed to international migration less by taking in than by sending out migrants. It is the source of major shares of permanent immigration to Australia, Canada, and the United States. Substantial intraregional labor migration has also developed, since 1973, to the capital-rich nations in the Persian Gulf and, since the mid-1980s, from East and Southeast Asia to Japan, South Korea, Hong Kong, Singapore, and Malaysia. Asia has recently exhibited more varied and dynamic flows of international migrants than any other region. The continent accounted for almost half the demographic quakes around the world between 1970 and 1995. The causes of these massive and unpredicted changes in population growth were multiple and varied. For example, large-scale labor migration, following the 1973 oil price rise, accounted for substantial demographic change in relatively small countries, particularly Kuwait, the United Arab Emirates, and Qatar, as well as among source countries, in Jordan and the Gaza Strip. In other cases, war and civil conflict, or subsequent repatriations, produced large migratory flows involving Afghanistan, Cambodia, and Lebanon. In proportion to population, these flows dwarfed the typical flows of migrants in more settled times. Because of the Persian Gulf War, for instance, Kuwait during 1990-1995 had an annual net migration rate of −70.2 per thousand, meaning that, over 5 years, migration reduced the population by 30 percent. All in all, Asia accounted for 36 percent of the 13.2 million refugees of concern to the U.N. High Commissioner for Refugees as of the end of 1996. These figures do not include the 3 million Palestinian refugees administered to separately, for historical reasons, by the U.N. Relief and Works Agency. Latin America and the Caribbean had a stock of nearly 7.5 million migrants in 1990 and a net migration rate, for the region as a whole, of −1.2 per thousand in 1990-1995. Much higher net emigration was visible in the Caribbean and Central America than in South America. Of the numerous, often small countries in the Caribbean and Central America, almost three times as many lost migrants as gained them. Mexico is the principal source country for migrants, with the United States as the country of overwhelming attraction. A modest amount of economic migration also takes place between Latin American countries, notably toward Argentina and Venezuela, some of it facilitated by regional trade agreements. In specific periods, however, migrants have also
OCR for page 164
BEYOND SIX BILLION: Forecasting the World's Population moved out of these countries. During the 1990s, economic difficulties led people of European origin to leave Argentina and Venezuela for Europe, while people of Japanese origin moved from Brazil to Japan. The number of refugees in the region is declining (to 88,000 in 1997), although crisis migration does occur—in 1994, for instance, from Haiti and Cuba—illustrating again the unpredictability of population movements. The United States, Canada, and Australia are the major traditional countries of permanent immigration. Northern America had a stock of 23.9 million migrants in 1990 and a net migration rate of 3.4 per thousand for 1990-1995. Oceania had a stock of 4.7 million migrants in 1990 and an identical net migration rate of 3.4 per thousand for 1990-1995. (Australia and New Zealand by themselves had a net migration rate of 5.1 per thousand.) Collectively, the traditional countries of immigration received 55 million migrants from Europe between 1800 and 1925. These flows slowed with World War I and came to a halt with restrictive immigration laws and global economic depression in the 1930s. When migratory flows picked up again after World War II, migratory patterns had changed considerably, and each receiving country has been on a somewhat different path dictated at least partly by national policy. In 1970, 60 percent of the foreign-born in the United States were of European origin. Since then, the picture has shifted dramatically, and well over half the foreign-born are now from Mexico, Asia, or Central America. Of legal immigrants entering the United States in 1996, 75 percent were from these regions (U.S. Immigration and Naturalization Service, 1997). As of its 1990 census, the foreign-born population of the United States stood at about 20 million or about 8 percent of the U.S. population (United Nations, 1995:Table 1, note 2)—making up, therefore, a sixth of all migrants around the world. Since then, and especially following passage of the 1990 Immigration Act, migrants entering the United States for lawful permanent residence have risen substantially, from 656,000 in 1990 to 911,000 in 1996 (U.S. Immigration and Naturalization Service, 1994:32, 80, 81),5 far more than the 360,000 a year in the late 1960s. Overall, these figures probably understate net migration. On one hand, they do not take 5 These figures were derived by taking the number of immigrants admitted, excluding the number whose “admission” in a given year was actually an adjustment of status (that is, refugees who had entered in prior years and illegal aliens legalized under the 1986 Immigration Reform and Control Act), and adding the number of refugees who physically entered the United States in the given year.
OCR for page 165
BEYOND SIX BILLION: Forecasting the World's Population account of the departure of emigrants, who, estimates suggest, have historically run at about one-third the number of immigrants. On the other hand, they do not include the entry of asylum seekers (who under U.S. law are distinguished from refugees and numbered 84,800 in 1997) or the entry of people admitted on multiyear but nonpermanent “nonimmigrant” visas.6 In addition, these numbers exclude those whose previously undocumented status was legalized under provisions of the Immigration Control and Reform Act of 1986. These people were counted by the U.S. government as immigrants at the time of legalization, producing a distorting spike in official statistics of 3 million in the past decade. Finally, the figures also leave out continuing net flows of illegal immigrants of about 275,000 a year. The stock of illegal immigrants had reached about 5 million by 1996 (U.S. Immigration and Naturalization Service, 1999; see also Warren, 1997). Like the United States, both Canada and Australia have experienced a notable shift to Asian source countries over the past decade. Although annual intake in both Canada and Australia is much lower than in the United States, the proportions of foreign-born in the total populations are considerably higher: over 17 percent in Canada and 21 percent in Australia. In recent years, Canada's annual intake of permanent settlers has exhibited a broadly downward trend, from a high of nearly 256,000 in 1993 to 226,00 in 1996. Annual immigration to Australia has fluctuated from a decade low of 69,800 in 1994 to 85,800 in 1997. With planned reductions in family-based programs, only 68,000 permanent-residence visas were to be issued in 1998, but intake under the Temporary Resident Programme has risen (Organisation for Economic Co-operation and Development, 1998:228-231). Western Europe (defined here to include all of continental Europe except for Eastern Europe and the former Soviet Union) had a stock of 22.9 million migrants in 1990 and a net migration rate of 1.9 per thousand population for 1990-1995, average for industrial regions. The U.N. defines Western Europe more narrowly to include only Austria, Belgium, France, Germany, Luxembourg, the Netherlands, and Switzerland. For this smaller region, the net migration rate for 1990-1995 is considerably higher 6 The figure for asylum seekers is from the U.S. Committee for Refugees (1998:12). As to temporary visas, there were in 1993 over 21 million such admissions, including multiple admissions of the same individual. Categories of persons admitted on temporary visas include nearly 17 million tourists, as well as business people, treaty traders and investors, and students and trainees and their spouses and children (U.S. Immigration and Naturalization Service, 1994:104).
OCR for page 166
BEYOND SIX BILLION: Forecasting the World's Population at 4.3 per thousand. These core Western European countries all gained population through migration in 1990-1995, but some insist that they are not “countries of immigration.” Migration to the region has been encouraged in various ways in the past. Europe initiated relatively large-scale labor recruitment in response to labor shortages during reconstruction after World War II. In the late 1960s and early 1970s, the core Western European countries were admitting upward of 1 million “guest workers” annually, ostensibly on a temporary basis. Large numbers of these were from Turkey, Yugoslavia, and the Southern European countries—Greece, Italy, Portugal, and Spain. Such recruitment was halted or slowed during the early 1970s as a consequence of rising public concern and the economic recession that followed the oil price rises of the period. However, the inflow continued, primarily because of provisions for family reunification. By the late 1980s, average annual immigration had risen dramatically to more than 1 million per year and in 1992 exceeded 1.7 million (Organisation for Economic Co-operation and Development, 1995:195). The totals were also swelled by new East-West flows and by asylum seekers, whose numbers began to rise dramatically in the mid-1980s and reached nearly 700,000 in 1992. Although only a small proportion of asylum seekers were found to have legitimate claims to refugee status, until recently most remained in the host countries. Since 1993, however, Western European governments have felt pressure to restrict immigration, which is on the decline in most countries, notably in Germany and France. By 1996, the number of asylum seekers especially had dropped to roughly a third of their 1992 level (United Nations High Commissioner for Refugees, 1997:185). However, illegal immigration may be on the rise. One estimate puts the stock of illegal immigrants in the region at 2.5-3.0 million; other estimates run as high as 5.5 million (Inter-governmental Consultations on Asylum, Refugee and Migration Policies in Europe, North America and Australia, 1995:6; International Centre for Migration Policy Development, 1994:63). Eastern Europe and the former Soviet Union had a stock of migrants of somewhat over 2 million in 1990 and a net migration rate of 0.9 per thousand for 1990-1995. More countries lost than gained population in that period. During the cold war, emigration from Eastern Europe and the Soviet Union was officially restricted. Beginning with the fall of the Berlin Wall in 1989, however, legal constraints on international mobility have been substantially eliminated, and Eastern Europe is increasingly a part of the expanding system of international movements of people, as well as capital, goods, services, and ideas.
OCR for page 177
BEYOND SIX BILLION: Forecasting the World's Population constant-migration assumption would have produced less error in five-year projections, and marginally less error in 10-year projections. In longer projections, however, the zero-migration assumption would have been more accurate. Figure 6-4 also shows a third alternative assumption, labeled “differentiated”: assuming a constant number of net immigrants for each industrial country, with the numbers distributed as emigrants across all other countries in proportion to population. For longer-run projections, this differentiated approach appears to be more accurate on average than the undifferentiated constant-migration approach and closer in accuracy to the zero-migration approach. Further careful differentiation of patterns across countries, therefore, could potentially lead to more accurate projections. An especially large contribution to accuracy would result from an ability to predict crisis migration. Figure 6-4 demonstrates this: whichever migration assumptions are used, migration error is considerably smaller when calculations exclude countries that have experienced a demographic quake—a sudden and extreme change in the population growth rate—which is most often associated with crisis migration. This exercise suggests that the procedures currently used to project migration, while they produce substantial errors, may be hard to improve on. To allow migration in the short term to depend on previous country experience appears sensible. To differentiate among countries also appears reasonable, although the specific ways in which countries are distinguished have not been assessed. Allowing long-run net migration to decline to zero may be no worse than other possible assumptions, in view of the difficulty of predicting the durability of past migration flows and the sources and directions of new flows. However, such assumptions are not meant as and are not likely to become valid predictions of future trends. If a way exists to model future migration trends more accurately, it may require more careful distinctions among countries and some attempt to anticipate crisis migration—neither of which is an easy task—or some complex definition of trends in between zero and constant migration. IMPROVING MIGRATION PROJECTIONS The limitations of migration projections are not easy to remedy. They are partly rooted in the nature of current migration trends, exacerbated by inadequate data and the sensitivity of migration to government intervention. These limitations are unlikely to be overcome in the short term, but a longer-term program of data collection and the appropriate use of theory
OCR for page 178
BEYOND SIX BILLION: Forecasting the World's Population to build dynamic models of migration may have some potential eventually to produce greater accuracy. Limitations in Projecting Migration While levels of fertility and mortality are in a historic transition that has brought them to low levels in all industrial countries and in many developing countries and that is being replicated in other developing countries (see Chapter 3, Chapter 4 and Chapter 5), a similar clear trend is difficult to define in the case of international migration. Worldwide, migration is not declining; in many regions and countries, it is rising, and no natural limits apply to it. Migration projections, therefore, have no strong and consistent trends that can serve as the backbone of credible projection assumptions for the future. Migration data also tend to be worse than fertility or mortality data, providing debatable estimates of current levels and an inadequate base of past trends for analysis, modeling, and extrapolation. Some governments want to track immigration, but the immigrants themselves (especially when they do not have legal status) may want to avoid being counted. Other governments, for political or ideological reasons, may not want to know the true numbers of migrants or the size of inflows, much less the characteristics and geographic distribution of these new residents. Where emigrants are concerned—and migration projections depend on knowing their numbers, too—government incentive as well as capacity to track movements tends to be even weaker. Which movements governments actually track and report varies and is subject to political definition. For example, the German government provides a “right of return” to ethnic Germans whose forebears migrated centuries ago and does not count them as immigrants if they move “back” to Germany. Other governments do not count foreign workers on temporary visas as immigrants, even if they have been in the country for many years. And refugees—even those long resident outside their countries—are often not counted as immigrants, especially if they are in camps supervised by the U.N. High Commissioner for Refugees. The compilation of any relevant data is itself becoming the subject of debate, especially in France, where some critics even question the legitimacy of collecting, analyzing, and projecting data on nationality, country of birth, race, ethnicity, and self-identification—demographic categories essential in identifying migrants. However defined and measured, migration flows can be strongly affected by government actions. While policies to affect fertility and mortality also exist, even when successful they seldom can have an impact as quickly as can migration policy. Migration projections should take policy
OCR for page 179
BEYOND SIX BILLION: Forecasting the World's Population into account, but since policy changes are difficult to predict, this adds to the uncertainty of the projections. When national statistical agencies make their own projections of international migration trends, these are more likely to reflect judgments about what is politically desirable rather than rational calculations of what is likely (Zlotnik, 1989). Using Migration Theory Migration theory does not provide a solution to such problems, but it does provide an approach to understanding the basic process. No complete migration theory exists, but a synthetic account of the relevant factors can be drawn from several theoretical traditions, including neoclassical economics, world systems theory, the “new economics” of labor migration, segmented labor market theory, social capital theory, and the theory of cumulative causation.11 This synthetic account does not cover crisis migration, which is not well integrated into theoretical discussions. But it does attempt to address several fundamental issues about other migratory movements: what forces promote emigration from countries of origin; what forces attract immigrants into countries of destination; what are the motivations, goals, and aspirations of the people who respond to these forces by migrating; and how social and economic structures arise to connect origin and destination areas. Contemporary international migration originates (according to world systems theory) in the social, economic, political, and cultural transformations that accompany the “penetration of capitalist markets into non-market or premarket societies.” Without such initial contact, local communities will not have the information, resources, or potential assistance essential to facilitate international migration. World systems theory emphasizes the disruptions of existing social and economic arrangements produced by markets and capital-intensive production technologies, including the displacement of people from customary livelihoods. Researchers do not agree, however, whether such displacement is essential before workers begin to search for new ways of earning income, managing risk, and acquiring capital. People seek to ensure their economic well-being (according to neoclassical economics) by selling their labor in markets that emerge with development. Because expected wages are generally higher in urban than in rural areas (even if the probability of securing an urban job may be 11 This section draws on a recent comprehensive review of migration theories (Massey et al., 1998, which provides further references) and their consistency with observed world patterns (United Nations Economic Commission for Europe, 1995:6; Morvant, 1996).
OCR for page 180
BEYOND SIX BILLION: Forecasting the World's Population low), one result is rural-urban migration. International migration is the next link in the chain, motivated by similar factors, because wages can be even higher in other countries. Researchers consistently find a significant correlation between wages in destination countries and emigration from origin countries. International wage differentials are coupled with other economic factors motivating people to migrate (according to the “new economics ” of labor migration). Although some people migrate to reap higher lifetime earnings, households also use international migration as a means of managing risk and overcoming barriers to capital and credit. By sending members abroad to work, households diversify their labor portfolios to control risks stemming from unemployment, crop failures, or price fluctuations. Foreign labor also permits households to accumulate cash for large consumer purchases or productive investments, or to build up savings for retirement. Migration helps households compensate for poorly developed or nonexistent markets for insurance, futures, capital, credit, and retirement. In the destination countries (according to segmented labor market theories), many migrants are shunted into a secondary labor market created by postindustrial transformation. With low pay, little stability, and few opportunities for advancement, this secondary market repels natives and generates a demand among some employers for immigrant workers. This process of labor market bifurcation is most acute in global cities (according to world systems theorists), where a concentration of managerial, administrative, and technical expertise leads to a concentration of wealth and a strong ancillary demand for low-wage services. While recruitment may be instrumental in initiating immigration, it becomes less important over time because the processes of economic globalization create links of transportation, communication, politics, and culture and make the international movement of people increasingly cheap and easy (as world systems theorists argue). Migration is also promoted by foreign policies and military actions taken by “core capitalist nations” to maintain international security, protect foreign investments, and guarantee access to raw materials—entanglements that create links and obligations and often generate ancillary flows of refugees, asylum seekers, and military dependents. A migration stream, no matter how it begins, displays a strong tendency (according to social capital theory) to continue because of the growth and elaboration of migrant networks. The concentration of immigrants in certain destinations creates a “family and friends” effect that channels later cohorts of immigrants to the same places and facilitates their arrival and incorporation. Moreover (segmented labor market theory argues), if enough migrants arrive under the right conditions, an enclave
OCR for page 181
BEYOND SIX BILLION: Forecasting the World's Population economy may form, which further augments the specialized demand for immigrant workers. 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. The expansion of networks that support migration tends to become self-perpetuating over time (according to the theory of cumulative causation), because each act of migration causes social and economic changes that promote additional international movement. If receiving countries implement more restrictive policies to counter rising tides of immigrants (argues social capital theory), this may even create a lucrative niche for enterprising agents, contractors, and other middlemen who create migrant supporting (or human trafficking) services. As economic growth in sending regions occurs, international wage gaps gradually diminish and well-functioning markets for capital, credit, insurance, and futures come into existence, progressively lowering the incentives for emigration. If these trends continue, the country ultimately becomes integrated into the international economy as a developed, capitalist society, whereupon it undergoes a migration transition: massive net emigration ceases and the country shifts to net immigration. Even before wage parity between countries is achieved, as long as a certain threshold of well-being is reached, migration may slow or cease with the increase in the “amenity costs ” of migrating (that is, the costs of leaving the familiar surroundings and social capital of one's homeland). Research to Improve Projections Migration theory therefore suggests a natural history to migration streams. Portions of this natural history have been modeled for specific countries and periods. For the flow of Mexicans to the United States from 1965 to 1995, for instance, Massey and Zenteno (1999) demonstrated the importance of the accumulation of migratory experience in Mexico. Without taking this accumulation into account and assuming instead a constant propensity to migrate (differentiated only by age and sex), by the end of the 30-year period one would have underestimated the cumulative total of Mexicans with migratory experience by 11 percent and underprojected the Mexican population living in the United States by 85 percent. Assuming instead that propensities to migrate change as migratory experience accumulates, Massey and Zenteno produced a more accurate simulation of the migration stream. With a similar dynamic model, Hatton and Williamson (1998) used the accumulated stock of the foreign-born and immigrants in the prior year to predict the subsequent flow of immigrants into five receiving
OCR for page 182
BEYOND SIX BILLION: Forecasting the World's Population countries over the period 1850-1914. Their equations showed very strong and significant effects of these variables and demonstrated clearly that migration flows were in excess of those predicted by economic differentials between countries alone. During this period, the five countries imposed no numerical limits on immigrants, a situation profoundly different from today, when such limits are universal. While these historical findings cannot therefore be easily translated to the present, they nonetheless suggest the type of modeling that may be possible.12 Dynamic models such as these clearly require considerable development and are not ready for application to projections for any country, much less to projections for all countries of the world. These models do not incorporate the constraints imposed by national immigration policies, a limitation that might be remediable with appropriate policy indicators. The models focus on predefined source and destination countries; predicting new streams that have no substantial precursors is a much more challenging exercise. The models capture only portions of the history of specific streams. The coexistence of multiple streams in different directions, some of them on the decline rather than in ascendance, helps explain why net migration into any country does not simply grow indefinitely. Perhaps most important, the models leave out crisis migration, a category of movement that is not easily anticipated. Preventing the conflicts and disasters that generate such migration is, of course, the proper initial focus of international concern, but anticipating the possibility of such events is an essential means to this end. Predicting such events is not, however, a task for which demography provides appropriate tools, and until political scientists and others develop the means to make such predictions, the best that population forecasters can do is to assess such flows as soon as they occur, revise projections appropriately, and model the likely future movements that may occur. CONCLUSIONS Patterns and Trends On average, international migration produces small annual changes in national populations; for half of all countries, the usual gain or loss is 12 Similar dynamic equations have been used by Walker and Hannan (1989) to predict not only the number of immigrants to the United States but also their geographic distribution. With contemporary rather than historical data, they showed that flows from specific countries tended to be channeled to states with recently arrived immigrants from the same countries or an accumulated stock of such immigrants.
OCR for page 183
BEYOND SIX BILLION: Forecasting the World's Population smaller than 0.2 percent. A steady stream of migrants can produce substantial accumulations over time, however, and their offspring, particularly if their fertility remains higher than that of the native population for some period, will add to population growth. For small countries in particular, international migration has considerable potential to alter population size and structure rapidly and substantially. Current patterns of movement are complex and go in many directions. Major streams flow toward various industrial countries, and, within particular world regions, migrant streams have developed toward the more advanced, the richer, or the more rapidly developing economies. Complicating the pattern are flows of crisis migrants, often driven by war or civil conflict, producing rapid and extreme changes in the demography of the smaller countries thus affected. Future movements should mirror these patterns to some extent. On one hand, increasing globalization could sustain and possibly enhance the volume of worldwide movement. Also contributing should be the dismantling of barriers to emigration that existed in many parts of the world until the early 1990s and that may also eventually give way in China. On the other hand, restrictive immigration policies in industrial countries are also spreading and will most likely continue to be strengthened, arresting these developments, although arguably not reversing them. Net international migration has often been treated as a residual factor in world demographic projections. Even the agencies involved recognize that this is unsatisfactory, although they may not be fully aware of its impact. Migration error is on average as important as fertility error in producing error in projected population, although much of this is due to the inability of forecasters to anticipate crisis migration. Over two decades, in addition, net migration into industrial countries has been underprojected. With net migration having become almost equal to natural increase in industrial regions, such errors could become increasingly consequential. Contemporary migration theory can be mined to provide an account of the natural history of a migration stream. Migrant flow tends to start only when a country attains some minimal level of development (provided a suitable destination is available), is impelled by the economic advantages that migrants foresee, is buttressed by accumulating migratory experience and the resulting development of interpersonal and institutional networks, and does not diminish until the sending country reaches some comfortable level of living comparable although not necessarily equal to that in the destination country. Such insights have been incorporated into a few dynamic models for migration that might eventually provide the means to substantially improve migration projections.
OCR for page 184
BEYOND SIX BILLION: Forecasting the World's Population Research Priorities In order for projections of international migration to improve, several things are required: Improved data. Without political commitment across countries, the accuracy of data on migration is unlikely to improve substantially. Countries need to adopt international standards and definitions for international migration, such as those proposed by the U.N. (1998a), rather than the more political definitions that now prevail. It would help too if some simple census tabulations could be made universal, particularly the tabulation of residents by place of birth and, for the foreign-born, by year of entry. This would facilitate a variety of indirect estimates of trends and patterns of international migration. Dynamic models. To this point, projections have been based on static assumptions—that levels and patterns of future migration will be like those in the past, or will decline to zero. Research has made clear that migration in the past increases the likelihood of migration in the future, and projection models should take into account this dynamic feedback loop. Studies of crisis migration. Much may be gained from close study, in an interdisciplinary context, of past incidents of crisis migration. While research may not lead to prediction of such incidents, it may facilitate prediction of the volume of flows and the prospects for repatriation. Most importantly, it may help avert such incidents in the future—which would also make projections more accurate. Measuring the openness of immigration and emigration policies. A key variable in projecting future migration flows is the relative openness of migration policies, within both sending and receiving nations. To date, little attention has been paid to the emigration policies of developing nations, yet these are likely to loom much larger in the future than in the last 50 years. More attention has focused on measuring the restrictiveness of immigration policies within receiving societies (e.g., Meyers, 1995; Timmer and Williamson, 1998), and this knowledge needs to be integrated into projection algorithms. Measuring the effectiveness of policy. Although most states seek to impose restrictions on international movement, they will not be equally effective. Recent research has suggested dimensions along which state effectiveness is likely to vary (Massey, 1999), but further work is needed to quantify effectiveness. A better understanding of this issue would provide a means of predicting the impact of policy on migration flows.
OCR for page 185
BEYOND SIX BILLION: Forecasting the World's Population REFERENCES Arnold, F. 1989 Revised Estimates and Projections of International Migration. Policy, Planning, and Research Working Paper 275. World Bank, Washington, D.C. Bos, E., M.T. Vu, E. Massiah, and R.A. Bulatao 1994 World Population Projections 1994-95 Edition: Estimates and Projections with Related Demographic Statistics. Baltimore: Johns Hopkins University Press. Gupta, P. 1998 International Migration and Fertility: Individual, Biological, and Social Effects. Unpublished manuscript. University of Pennsylvania, Philadelphia. Hatton, T.J., and J.G. Williamson 1998 The Age of Mass Migration: Causes and Economic Impact. Oxford, Eng.: Oxford University Press. Hill, K. 1990 Proj3S: A Computer Program for Population Projections. Washington, D.C.: World Bank. Inter-governmental Consultations on Asylum, Refugee and Migration Policies in Europe, North America and Australia (IGC) 1995 Illegal Aliens: A Preliminary Study. Geneva: Secretariat of the Inter-governmental Consultations on Asylum, Refugee and Migration Policies in Europe, North America and Australia . International Centre for Migration Policy Development 1994 The Key to Europe: A Comparative Analysis of Entry and Asylum Policies in Western Countries. Swedish Government Official Report No. 135. Stockholm. Levitt, P. 1998 Social remittances: Migration driven, local-level forms of cultural diffusion. International Migration Review 32(Winter):926-948. Massey, D.S. 1999 International migration at the dawn of the twenty-first century: The role of the states. Population Research and Policy Review 25:303-322. Massey, D.S., and R. Zenteno 1999 The dynamics of mass migration. Proceedings of the National Academy of Sciences U.S.A. 96:5328-5335. Massey, D.S., J. Arango, G. Hugo, A. Kouaouci, A. Pellegrino, and J.E. Taylor 1998 Worlds in Motion: Understanding International Migration at the End of the Millennium. Oxford, Eng.: Oxford University Press. McEvedy, C., and R. Jones 1978 Atlas of World Population History. Middlesex, Eng.: Penguin. Meyers, E. 1995. The Political Economy of International Migration Policy: A Comparative and Quantitative Study. Ph.D. dissertation, Department of Political Science, University of Chicago. Morvant, P. 1996 Migration service releases 1995 data. OMRI Daily Digest No. 39, Part I, February 23. National Research Council 1997 The face of U.S. population in 2050. Pp. 76-134 in National Research Council, The New Americans: Economic, Demographic, and Fiscal Effects of Immigration . Panel on the Demographic and Economic Impacts of Immigration. J.P. Smith and B. Edmonston, eds. Committee on Population and Committee on National Statistics, Commission on Behavioral and Social Sciences and Education. Washington, D.C.: National Academy Press.
OCR for page 186
BEYOND SIX BILLION: Forecasting the World's Population Organisation for Economic Co-operation and Development 1995 SOPEMI: Trends in International Migration: Annual Report 1994. Paris: Organisation for Economic Co-operation and Development. 1998 SOPEMI: Trends in International Migration, Continuous Reporting System on Migration, Annual Report, 1998 Edition. Paris: Organisation for Economic Co-operation and Development. Orubuloye, I.O., P. Caldwell, and J.C. Caldwell 1993 The role of high-risk occupations in the spread of AIDS: Truck drivers and itinerant market women in Nigeria. International Family Planning Perspectives 19(2):43-48, 71. Russell, S.S. 1996 International migration: Global trends and national responses. Fletcher Forum of World Affairs 20(2):1-15. Timmer, A.S., and J.G. Williamson 1998 Immigration policy prior to the 1930s: Labor markets, policy interactions, and globalization backlash. Population and Development Review 24:739-772. United Nations (U.N.) 1989 The United Nations Population Projection Computer Program: A User 's Manual. New York: United Nations. 1995 Trends in Total Migrant Stock. Revision 1. New York: United Nations. 1998a Recommendations on Statistics of International Migration. Revision 1. Statistical Papers, Series M, No. 58, Rev. 1. New York: Statistics Division, United Nations Department of Economic and Social Affairs. 1998b World Population Monitoring 1997: International Migration and Development . New York: Population Division, United Nations Department of Economic and Social Affairs. 1999 World Population Prospects: The 1998 Revision, Vol. 1, Comprehensive Tables. New York: United Nations. United Nations Development Programme (UNDP) 1999 Human Development Report 1999: Globalization with a Human Face. Oxford, Eng.: Oxford University Press. Retrieved September 1999 from the World Wide Web at http://www.undp.org/hdro/99.htm. United Nations Economic Commission for Europe 1995 International Migration Bulletin No. 7 (November). Geneva: United Nations. United Nations High Commissioner for Refugees 1997 The State of the World's Refugees 1997-1998. New York: Oxford University Press. U.S. Census Bureau n.d. Making Population Projections. U.S. Census Bureau, Washington, D.C. U.S. Committee for Refugees 1998 World Refugee Survey 1998. New York: Immigration and Refugee Services of America. U.S. Immigration and Naturalization Service 1994 Statistical Yearbook of the Immigration and Naturalization Service, 1993. Washington, D.C.: U.S. Department of Justice. 1997 Statistical Yearbook of the Immigration and Naturalization Service . Washington, D.C.: U.S. Department of Justice. [ 1999] Illegal Alien Resident Population. Retrieved September 1999 from the World Wide Web at http://www.ins.usdoj.gov/graphics/aboutins/statistics/illegalalien/index.htm .
OCR for page 187
BEYOND SIX BILLION: Forecasting the World's Population Walker, R., and M. Hannan 1989 Dynamic settlement processes: The case of U.S. immigration. Professional Geographer 41:172-183. Warren, R. 1997 Estimates of the Undocumented Immigrant Population Residing in the United States: October 1996. Paper prepared for the Joint Statistical Meetings, Anaheim, Calif., August 13. World Bank 1999 World Development Indicators 1999. Washington, D.C.: World Bank. Zlotnik, H. 1989 Official population projections in OECD countries: What they reveal about international migration prospects. In Migration: The Demographic Aspects. Paris: Organisation for Economic Co-operation and Development. 1998 International migration 1965-96: An overview. Population and Development Review 24(3):429-468. 1999 World Population Prospects: The 1998 Revision. Paper submitted to the Joint ECE-Eurostat Work Session on Demographic Projections, Perugia, Italy, May 3-7.
Representative terms from entire chapter: