Net Migration Patterns Research Articles

Migration, fertility, and aging in stable populations

Fertility is below replacement level in all European countries, and population growth is expected to decline in the coming decades. Increasing life expectancy will accentuate concomitant aging of the population. Migration has been seen as a possible means to decelerate aging. In this article, I introduce a stable, open-population model in which cohort net migration is proportional to births. In this case, the migration-fertility trade-off can be studied with particular ease. I show that although migration can increase the growth rate, which tends to make the age distribution younger, it also has an opposite effect because of its typical age pattern. I capture the effect of the age pattern of net migration in a migration-survivor function. The effect of net migration on growth is quantified with data from 17 European countries. I show that some countries already have a level of migration that will lead to stationarity. For other countries with asymptotically declining population, migration still provides opportunities for slowing down aging of the population as a whole.

Vertical migration of postlarval penaeid prawns in two Australian estuaries: the effect of tide and day/night

Knowledge of the vertical migration behaviour of postlarval penaeid prawns is important in understanding postlarval migration from offshore spawning grounds to estuarine nursery areas. We sampled throughout several 24-h periods in two estuaries in Australia to assess the distribution of postlarvae in the water column. We used four trawl nets: one net in the top 0.5 m of the water column and three nets one above the other, from the seabed to 0.72 m above the seabed. Penaeus plebejus was abundant in catches in the Nerang River, southern Queensland, while Penaeus semisulcatus, Penaeus esculentus and Penaeus merguiensis were caught in the Embley River, northern Queensland. For all species, the highest catches at the surface were on night flood tides. Many postlarvae in the Embley River were caught in nets above the seabed on ebb tides, suggesting that net migration patterns cannot be determined simply by sampling surface waters. The vertical distribution of penaeid postlarvae is determined primarily by tide and day/night; however, water turbidity and cloud cover, factors that reduce light at the seabed, are also likely to be important. All these aspects of postlarval behaviour should be included in hydrodynamic models of larval advection from spawning grounds to inshore nursery areas.

Tracking cohorts: Analysis of migration in the early life stages of an estuarine fish

Larvae and juveniles are often most abundant at some distance from where spawning occurs. Such apparent distribution shifts can be the result of larval migration, seasonal shifts in the distribution of spawners, or spatial heterogeneity in mortality. In the present study, a cohort-based method was adopted to test for larval migration of bay anchovy (Anchoa mitchilli) and to estimate its rate and timing. A spatially and temporally extensive series of ichthyoplankton samples was collected in the lowest 122 km of the Hudson River in summer 1998. Bay anchovy eggs and young-of-year individuals were abundant (mean density=1.6 m−3 and 0.95 m−3, respectively). Daily age used to define cohort membership was determined from otoliths. Age and length were strongly related (R2=0.74). The age-length relationship varied over the season such that early-season bay anchovy hatched in June grew more rapidly than later-season anchovy hatched in August. Cohorts were defined as week-long birth-data classes, and net migration patterns of 11 cohorts were analyzed. Mean location shifted upriver as cohorts increased in age to 6 wk, at a net rate of about 0.6 km d−1. Cohort abundance usually decreased over time in downriver regions, but usually increased in upriver regions. The cohort analysis confirmed that the upriver shift in distribution of early-stage anchovy is not entirely due to changes in adult spawning behavior or to clines in larval mortality, and must be partly the result of larval migration.

On the intensity and balance of intra-European migration

This paper seeks to examine changes in the balance of intra-European migration during the years 1985-99. We construct two indices for measuring intra-European migration between each member state and the rest of the EU15. Non-parametric tests indicate that there is a close and increasing relationship between real GDP per capita and the pattern of net migration within Europe. Further, statistical tests suggest that, on the whole, intra-European migration has actually become more balanced after the implementation of the Schengen agreement in 1995. A Chow test also reveals that 1995 is the break-year after which levels of intra-European migration shifted upwards.

La migration interprovinciale des personnes nées à l’étranger, Canada, 1981-1986

"This article analyzes the spatial distribution as well as interprovincial migration of foreign-born persons living in Canada, using data from the 1986 census. The focus is placed on differences observed in migratory behaviour between native-born Canadians and those born abroad. Net migration patterns as well as the propensity to migrate by place of origin and destination are presented for different population groups according to birthplace. Finally, multiregional life tables are used to evaluate the effect of these migratory differentials on the retentive force exerted by the various regions." (SUMMARY IN ENG AND SPA)

Geography and Migration

This paper reviews and evaluates the contribution of contemporary geographical research to our understanding of internal and international migration. Four main conclusions are reached: (i) that geography is absolutely central to the study of migration (and vice versa); (ii) that, throughout the recent period, geographers have contributed greatly to migration research through their empirical studies of migration flows and net migration patterns (often using quantitative methods); (iii) that these analyses have tended, however, to understate the significance of the cultural, political and social aspects of migration, and have been biased towards certain advanced capitalist countries; and (iv) that future research should redress these imbalances.

Net migration and migration effectiveness: A comparison between Australia and the United Kingdom, 1976–96 Part 1: Total migration patterns

A nation’s population is redistributed through migration flows and counterflows between its constituent subnational areas, resulting in a geographical pattern of net migration gains or losses which may change from one time period to another. Migration effectiveness is the indicator commonly used to measure net migration as a proportion of gross migration turnover for any territorial unit. This paper explores the effect of net migration in two different countries, Australia and the United Kingdom, using measures of migration effectiveness computed from period-age migration data sets for a system of city regions assembled for four consecutive five-year periods in each country. While the evidence suggests that the overall effectiveness of net migration has declined over the 20-year period in both countries, marked similarities and contrasts are apparent in the spatial patterning of migration that together provide useful analytical insights into the changing space economies of the two countries.

Age selectivity and Inter-provincial net migration in Spain

This paper identifies the role of net migration in accounting for provincial population change in Spain between the 1960s and the 1980s. The changing geographical pattern of aggregate net migration is explained and new data from an unpublished 10% sample from the 1991 Census are used to examine age-specific net migration balances at the provincial scale for 1981-91. A classification of provinces is developed on the basis of net migration rate age schedules and migration efficiencies are computed to show the coastal provinces that have become the main areas of growth through net migration in the 1980s.

Migration and the life course: is there a retirement transition?

This paper focuses on pre-elderly (ages 55–64) net migration in the United States for the period 1980–90, to explore the hypothesis that there exists a ‘retirement transition’ that characterizes pre-elderly migration. While previous research has demonstrated variation in migration patterns over the life course, these studies generally imply that both migration motivations and destinations change abruptly at age 65. Little effort has been made to explore the migration behaviour of the pre-elderly as distinct from that of either younger or older age groups. This research uses ordinary least squares regression to compare the effects of demographic, economic, and amenity factors on county-level net migration rates for five age groups: the young (25–44), the middle-aged (45–54), the pre-elderly (55–64), the young-old (65–74), and the old-old (75+). Pre-elderly migration patterns emerge as distinct from those of both younger and older age groups. Their net migration patterns are not fully shaped by labour force considerations. At the same time, pre-elderly migration appears to be driven by factors beyond retirement. These findings are discussed in the context of life-course change and their implications for the ageing baby-boom cohorts. © 1997 John Wiley & Sons, Ltd.

Age and inter-county net migration in Great Britain

The net migration patterns of four age groups are analysed using National Health Service Central Register (NHSCR) inter-county migration data for the periods 1987/88 and 1990/91. Age is shown to have an important bearing upon the relative importance of various determinants of migration. The effect of the movement from national boom to deep recession is also commented upon.

Demographic Influences on the Number of Children at School Entry Ages, with Examples from Three States

"This paper analyzes the effects of changes in fertility, mortality, and net migration patterns on the growth of school entry-age populations in three states (Florida, South Carolina, and West Virginia) over the period 1950-1990. Fertility changes have had the largest influence on growth of these young populations, as common sense suggests. Changing migration patterns have been quite important, however, in explaining intertemporal and interspatial variations in growth rates."

POTENTIAL CHANNELS OF IMMIGRANT INFLUENCE ON THE ECONOMY OF THE RECEIVING COUNTRY

ABSTRACT Immigrants may affect natives through a number of channels. Among these many channels of influence, the production theory and public sector channels have been most frequently studies in the context of contemporary U.S. immigration. Other channels that may be important are changed local demand for final goods and services (including that generated by immigrant wealth); indirect and induced demands for factors of production, demand for fixed capital (e.g. housing) and land, technological change, scale and agglomeration economies, unemployment, labor fore participation, inflation, balance of payments, regional and national net experts, internal migration, remittances, externalities and fertility patterns. This paper discusses certain problems with the use of the production theory and public sector channels and also describes the potential importance of other channels, as indicated for other countries and/or for the U.S. during other periods of time. While these alternative channels may sometimes reinforce the two they frequently run counter to them.

The turnaround in Australia: some first observations from the 1991 census.

"The aim of this paper is to utilise recently released census results to examine patterns of population change in non-metropolitan Australia during the 1986-91 period, focusing particularly upon the net migration component of that change. The paper presents an overview of recent trends in population change in non-metropolitan areas and then moves to an analysis of net migration patterns in non-metropolitan local government areas during the late 1980s using a Life Table Survival Ratio technique to estimate net migration. It appears that the trends observed in the early 1980s have continued into the late 1980s and early 1990s, and that overall the 'turnaround' is slowing down and becoming more diversified, more complex, and much less predictable in the 1990s."

A Theoretical Foundation for the Concept of Differential Urbanization

This paper develops a theoretical foundation for the notion of differential urbanization, in which groups of large, intermediate-sized, and small cities go through successive periods of fast and slow growth in a continuum of development that spans the evolution of urban systems in developed and less developed countries. A model depicting net migration patterns over time for major metropolitan, intermediate-sized, and small urban areas identifies six stages of differential urbanization. Data from three countries that span the development spectrum are used to test the accuracy of this model. A distinction between mainstream and substream migration flows provides an indicator of the concurrent concentration and deconcentration forces shaping urban systems. Counterurbanization represents the final phase in the first cycle of urban development, and is followed by a second cycle in which urbanization and spatial concentration dominate once again. At advanced levels of urbanization, the model can be used to characterize the degree of development within regions or subregions of a country. Also, precise definitions are suggested for the “clean break,” the end of urbanization, and the beginnings and ends of polarization reversal and counterurbanization.

Migration, Race and Ethnicity, 1960–1980

"This article compares racial and ethnic patterns in interstate and interregional migration in the years 1960 to 1980.... This research looks at geographical assimilation--the extent to which patterns of migration and regional distribution of minority groups resemble those of whites. Attention is directed to United States-born Asian Americans, blacks, Hispanics, Native Americans and whites, and attempts to answer the following questions: 1) To what extent do the patterns of interstate migration of these groups resemble one another? 2) To what extent do the regional distributions and patterns of net regional migration of these groups resemble one another?" This is a revised version of a paper originally presented at the 1988 Annual Meeting of the Population Association of America (see Population Index, Vol. 54, No. 3, Fall 1988, p. 495).

The Internal Migration in Modern Japan

Abstract Japan has experienced a long and complex migration process. This process has been accompanied by a long and slow out-migration from rural to urban areas before the World Wars as a result of the industrialization process. Population were concentrated around the Tokaido megalopolis—the area along the Pacific coast between Tokyo and Osaka during the period of rapid economic growth in the 1950s and 1960s, and then suburbanization appeared in the areas surrounding the large metropolises in the later period. After the oil crisis in 1973, migration movement to the megalopolis reduced and the so-called “U-turn” movement emerged with migration dispersed to other regions and heading first to local areas. However, after 1983, population again concentrated towards the megalopolis. In this paper, the key features and factors leading to the change in the process of internal migration are reviewed. Also, the patterns of net migration in the period of 1956–1990 for the prefectures are categorized for further research.

ECONOMIC REGION NET MIGRATION PATTERNS IN THE USSR: 1979-89

"This article investigates economic region net migration patterns in the USSR during the 1979-89 intercensal period. Net in-migration and net migration rate increases (compared to 1970-79) occurred in both the western and eastern portions of the Northern USSR region, while net out-migration and rate declines occurred throughout the Southern USSR. Net in-migration again occurred to Siberia, especially Tyumen' Oblast, and there was a reduced rate of net out-migration from the Nonchernozem Zone and Central Chernozem Region of European RSFSR."

Post-1980 Regional Migration Patterns of the U.S. Elderly Population

We investigated how three aspects of the U.S. elderly population's residential relocation behaviors have changed over the past three decades (1955-60, 1965-70, 1975-80, 1980-85): their rates of overall mobility, interstate, interregional, and intracounty moves; their interregional origin-destination migration streams; and their regional net migration patterns. Data were obtained from published reports of the 1960, 1970, and 1980 U.S. Decennial Censuses and the 1985 U.S. Current Population Survey. Overall mobility rates consistently declined in all regions and periods, while interstate and interregional migration rates increased through 1980. In the period 1980-85 there were decreased numbers and rates of elderly out-migrants from the Midwest and Northeast, resulting in unprecedented declines in the net migration gains of older persons in the South. The likely persistence of these trends in the future and their explanation are discussed.

Otero County: A demographic history of a Colorado High Plains County, 1889–1987

Otero County, situated on the High Plains of eastern Colorado, typifies many rural agricultural counties. This article surveys its history, demography, and social economy during the period from its formation in 1889 to 1987. It compares the county's demographic changes with those of the state and presents the county's changing age composition and net migration patterns. Population composition correlates with economic opportunity. The demographic and economic trends present in Otero, and most other out-lying Colorado counties, run counter to those of the state as a whole.

A regional scale temporal analysis of the net migration patterns of elderly persons over time.

New England counties are grouped into categories using graphic displays of five decades of net migration rates for young and old elderly persons. Linear functions composed of social, economic, and geographic variables discriminate among the categories, yielding the following associations: positive rate counties are long-standing retirement and recreation areas; negative rate counties have large, old, declining cities; turnaround counties are nonmetropolitan counties with recently developed retirement/recreation facilities; miscellaneous counties include suburban counties with a temporary peak in net migration rates. The counties' patterns are relatively similar for young-old and old-old persons over the five decades.