The structure of interstate and interregional migration: 1965–1970

This study examines the structure present in interstate migration at the national level and interregional migration in the Western states in an attempt to identify the interrelationships that exist between the respective areal units. Places which act as important origins and destinations in the process are determined through the use of nodal and principal component analyses. It is found that the nation can be dichotomized into regions oriented towards the states of California and Florida and that the western part of the nation can also be regionalized into a small number of important migration fields. The centers of the majority of these fields are metropolitan areas. Such identification of the spatial organization provides a useful picture of the areal extents over which major attractive centers have influence.The author wishes to acknowledge the financial support of the Academic Senate Committee on Research, University of California, Santa Barbara, California.     

An economic analysis of migration in Mexico

This paper analyzes internal migration in Mexico over the 1960–1970 period. A model of the determinants of migration is specified and estimated for aggregated interstate migration flows. The results show that distance serves as a significant deterrent to migration, that higher destination earlings levels are attractive to migrants, and that regions with high unemployment rates experience lower rates of in-migration. An unanticipated finding is that regions with higher earnings levels have greater rates of out-migration.The data are disaggregated to examine separate migration relationships for each state. The results are that distance is a lesser deterrent for those migrants with more accessible alternatives, that higher earnings levels reduce the deterring effects of distance, and that regions with higher earnings levels have lower associated elasticities of migration.It is concluded that economic factors have played a crucial role in internal migration and thus in the changing occupational and geographic structure of the Mexican labor force.This research was supported by Grant Number 1-RO-1-HD08567-01 from the Population and Reproduction Grants Branch, Center for Population Research, National Institute of Child Health and Human Development, United States Department of Health, Education, and Welfare. Part of this study was completed at the Food Research Institute, Stanford University, where J. R. Ladman was a Visiting Scholar. We are grateful to Barry Edmonston and Dudley Kirk for their helpful comments on an earlier draft of the paper. Responsibility for remaining shortcomings remains ours.     

Information,communication and networks in international migration systems

This paper focuses on the role of information and communication in international migration by means of a survey which covers economic and broader perspectives, both at the micro and macro levels. The human capital model of migration is reviewed and the likely impact of recent and anticipated developments in telecommunications technology is noted. The job search model is reformulated in the context of international migration but extensive modification is required to describe the potential sampling of job offers and other informational needs of international migrants. It is argued that spatial selectivity is to a large extent influenced by migration networks in which information flows play a critical role. This is further elucidated by offering an analytical framework based on the systems approach to migration.     

Caesium-137 migration in Hungarian soils

Distribution of 137Cs activity concentration has been measured in soils from 19 Hungarian counties. The levels of soil contamination in Hungary after the Chernobyl fallout are sufficient to study the vertical distribution of the 137Cs under natural conditions. Samples were taken layer by layer on plain, grassy and uncultivated fields down to a depth of 20 cm. The results show that radiocaesium migrates very slowly in the soils investigated. The 137Cs concentration peaks in almost all of the soils remain in the top 5 cm layer, but the distribution patterns are different. Variations in diffusion, sorption-desorption, and complexing processes, plant uptake and plant- and animal-originated mechanical changes result in the formation of site-specific radionuclide distribution profiles. On the basis of the experimental data a model has been developed for the long-term prediction of the 137Cs migration. By application of an applied diffusion-convection model the results can be well fitted, the initial deposition can be calculated and the data can be used for the long-term prediction of the 137Cs distribution profile.     

The internal dynamics of international migration systems

"In this paper I provide a conceptualization of international migration networks, which can be used to identify and integrate the internal components of migration systems, and formalize the relationships in an analytic model of the internal network dynamic. With the use of the operationalized model, and microlevel and macrolevel data for guestworkers in Germany during the period 1970 to 1989, we can empirically test the relative influence of internal network variables versus external forces on the attraction of immigrants over time. The empirical results suggest that--as the system matures--network variables have an increasing impact on the attraction of immigrants, while the impact of economic factors declines. The research is concluded with a series of simulations that further highlight the internal dynamic of international migration systems."     

Volatility in the geographical structure of short-run US interstate migration

"Migration is often thought to be a long-run phenomenon. However, it is shown here by means of labor-force migration estimates derived from the Continuous Work History Sample over the period 1958-1975, that US interstate migration is quite volatile over the short run with respect both to its adjustment to macroeconomic fluctuations and to its geographic structure. A hierarchical clustering routine is utilized to analyse yearly estimates of interstate gross in-migration and out-migration so as to identify the temporal stability and characteristics of the geographical patterns of migration. States enter the national migration linkage tree at different levels for different years, depending upon the level of short-run economic activity." It is also shown that "when national economic conditions worsen, labor-supply adjustments are more localized and the degree of interstate interdependence is less than in times of economic boom."     

Interstate migration of college freshmen

We examine the economic determinants of interstate migration of college-bound freshmen, using state-level data. Our analysis provides a robust explanation of the striking differences among the U.S. states in out-migration of college-bound freshmen. States that provide more educational choices and higher quality education services, charge lower tuition, have broad-based merit scholarship programs and have lower income levels tend to retain a higher percentage of their college-bound freshmen at home. We thank Andrew Mason, Sang-Hyop Lee and Rhonda Sharpe and two anonymous referees for helpful comments and suggestions.     

基于高密度电阻率法的水分迁移模型试验研究

在土工模型试验中,常用的应用于水分及溶质迁移过程量测的传感器量测、图像分析及取样分析等方法并不能充分满足三维、无损、实时的量测需求。高密度电阻率成像法为土工模型试验中三维、无损、实时量测需求提供了新的解决思路。基于高密度电阻率成像法发展一套适用于常规物理模型及超重力离心环境中土体电阻率测试设备和分析方法,并通过开展模型试验验证其应用于水分迁移过程量测的适用性及有效性。常规物理模型试验(1g)表明,该设备及方法能够获得模型土体中电阻率的三维时空分布,入渗过程中电阻率与含水率的分布及变化合理反映电阻率与含水率定性关系;在低有效饱和度区间,电阻率法具有很高的灵敏度。离心模型试验结果表明,重力水平的变化可导致水分在模型土柱中的分布发生显著变化;实时量测技术及分析方法可为土工离心环境中渗流及溶质运移过程的分析提供更为准确的依据。高密度电阻率成像法可以成功应用于常规物理模型及超重力离心环境中水分迁移过程量测,并保证一定的精度和灵敏度。     

Spatial scale, return and onward migration, and the Long-Boertlein index of repeat migration

Abstract.  Long and Boertlein's (1990 ) measure of repeat migration can be used to infer the effects of repeat migration with data sets that did not specifically ask questions about such migration. While recent work by Rogers et al. (2003 ) evaluated how well this synthetic measure matched empirical fixed-interval measures, the role of spatial scale remains unclear, particularly since scale influences migration levels, spatial structure, and the representation of the primary, return, and onward migration components within the overall flow. Motivated by the implementation of the American Community Survey and the concurrent need to adjust data from one to five-year formats, and using the 1996 Canadian Public Use Microdata File and a custom tabulation from the 1996 Canadian census, the accuracy of the index is evaluated. In particular, the effects of spatial scale upon measures of primary, return and onward migration are described and evaluated, with the Long-Boertlein measure contrasted with fixed-interval measures of return and onward migration. Results show that the measure is sensitive to spatial scale.     

Crossing boundaries and borders: Regional science advances in migration modelling

Abstract. In this article we survey common themes in recent migration research and comment on the actual and potential contribution of regional science to this literature. There has been a marked shift in research from internal to international migration. The two research programmes would benefit from a unified framework. Spatial and systemic features of migration systems remain underdeveloped. Moreover, the perspectives from the different disciplines that intersect in regional science can still be integrated better. Communication of the research findings in terms understood by policymakers and practitioners is also desirable. Finally, many new and interesting research topics will emerge when greater effort is made to link migration research with other current research topics in regional science.     

Does crime affect migration flows?

The influence of urban externalities on migration flows has not been fully examined in the previous literature. This paper investigates whether a change in dwellings across cities is associated with a specific urban externality, crime rates, using urban‐to‐urban migration data at the municipal level. Gravity equation results show that migration is affected by crime rates, not only locally but also when neighbouring effects are taken into account.     

原状土冻融过程中水分迁移试验研究

为了量化原状土中水分在冻融过程中的迁移,试验采取在其他试验条件相同的条件下,改变初始含水率或温度模式的方法,研究了单个因素对水分迁移的影响。经冻结并融化到设定位置后,从试验中观察到试样未融化部分存在有横向和竖向的裂缝现象、明显的冻融分界线、水分积聚层和融化锋面并不在同一个层面内、土中水的冻结温度各不相同、冻结后含冰不均匀现象等结果,进而对冻融过程中进行温度场分析以及冻融前后含水率的变化分析,用具体试验数据得出如下结论:控制不同顶板温度时,不同含水率的试样中各点处温度的变化趋势基本相同;在顶板控温相同的情况下,初始含水率大的试样,水分迁移量大,水分积聚多;不同冻结温度和融化温度对试样中水分的迁移影响非常明显,顶板冻结时温度越高,水分积聚层位置处的含水率越大,水分积聚越多等。     

The determinants of elderly migration in France

The aim of this paper is to study elderly migration in France. First, it analyses whether the decision to migrate relies upon individual characteristics. Second, it examines the ways in which the economic, social and environmental characteristics of the French territories determine the retirees' choice of localization. The paper draws upon a unique database of 12.67 million French inhabitants, with information about their personal attributes and locational choices from 2003 to 2008. It also uses an original database with locational characteristics for the French territories at the level of the 364 zones d'emploi. This is the only study on regional migration in France which builds upon such a thin spatial level of analysis. The paper builds empirical probit and Heckman models dealing with selection bias and endogeneity bias issues. The paper shows that retirees usually leave large agglomerations and old industrial areas in Northern France and the Paris agglomeration and relocate to socially and environmentally attractive zones with preferable climates. When studying the migration patterns within the zones d'emploi, it appears that the most vulnerable zones, which display a lower quality of collective services as well as higher income disparities and crime rates, feature lower elderly residential mobility.     

Crossing boundaries and borders: Regional science advances in migration modelling

In this article we survey common themes in recent migration research and comment on the actual and potential contribution of regional science to this literature. There has been a marked shift in research from internal to international migration. The two research programmes would benefit from a unified framework. Spatial and systemic features of migration systems remain underdeveloped. Moreover, the perspectives from the different disciplines that intersect in regional science can still be integrated better. Communication of the research findings in terms understood by policymakers and practitioners is also desirable. Finally, many new and interesting research topics will emerge when greater effort is made to link migration research with other current research topics in regional science.JEL Classification: F22, J11, O15, R23     

On the relation between origin income and migration

While traditional migration theory suggests that the rate of migration is negatively related to income at the origin, many empirical studies of aggregate migration yield a non-significant or even a positive relation. This paper utilizes a simplified model of migration to demonstrate that one possible reason for such results is the imperfect capital market facing migrants. Higher average income at the origin may imply a higher number of individuals who have the cash resources to finance migration, thus generating a positive relation between regional income and migration. The conclusions suggest the use of non-linear specifications in empirical migration studies.The views expressed in this paper are the author's; they do not represent those of the World Bank or its affiliated institutions.     

Interregional labor migration and information flows

A model of interregional labor migration is developed that incorporates a complex system of information concerning migration and employment opportunities, as well as a heterogeneous population in which groups of workers differ in their assumed levels of skill, attitudes toward risk, and willingness to move. "Three channels are examined: interpersonal communication, general source information, and specific source information targeted at unemployed workers. In this process, trajectories of welfare levels (composed of wage plus nonwage benefits), information flows, vacancy and unemployment levels are generated for different worker and job types, regional aggregates, and the system as a whole. The behavior of the model is examined by means of numerical simulations and sensitivity analyses."     

Job-related migration in the Netherlands. The role of geographical access to employment in a polynucleated urban region

Over the last few decades, the Netherlands’ economic urban landscape has developed into a polynucleated urban structure. The resulting spatial distribution of job opportunities influences geographical job access at the individual level. This paper addresses the question, to what extent does spatial variation in job access within the Netherlands polynucleated urban structure influence job-related migration? First, it is shown that there are large differences in job access in the Netherlands in both the total number of jobs and in job levels. Scores on job access are higher in strategic residential locations in between the major cities in the polynucleated urban region of the Randstad than in the major cities themselves. Second, using data from the Netherlands Housing Demand survey and logistic regression models, it is shown that the probability of job-related migration decreases as the number of jobs within reach of the residence increases. The analyses control for both individual and household characteristics. The results show that strategic residential locations in between the major cities are as favourable as the cities themselves in terms of avoiding high spatial mobility costs.     

Mental map variability: A migration modeling problem

Mental map variability is important when viewed in a migration prediction context. Models that link aggregate mental maps of residential desirability to migration have limited predictive value because mental maps vary among socioeconomic groups and migrants often have very different socioeconomic characteristics than the general population within a source region. Residential desirability also varies with both the distance to and the intensity of awareness for alternative destinations. Utility can be increased by disaggregating the mental maps of potential migrants on the basis of accessibility to potential destinations, socioeconomic status, and awareness levels for alternative locations.The author wishes to acknowledge the thoughtful comments of Professor Richard Jones on an early draft of this paper. The assistance of Ms. Gail Leithauser who tabulated much of the data also proved most helpful.     

From school to university to work: migration of highly educated youths in China

A burgeoning body of the literature has studied the migration of university-bound students and university graduates in developed countries, but little research has been conducted on this issue in China. Using microdata from the 2005 1 % population sample survey, this paper examines, for the first time, the migration of university entrants and graduates in China by describing their migration patterns and modeling their choices of destination location. The migration patterns show that recent university graduates are highly concentrated in three eastern provincial units, Beijing, Shanghai, and Guangdong, and that the destinations of university entrants tend to be more dispersed geographically. The results from conditional logit models indicate that highly educated youths, in particular those who study in a regular university, have a strong tendency to stay in the same province after graduation. The migration of university entrants is determined mainly by regional differences in university enrollment, while the distribution of national key universities, economic opportunities, and the cost of living plays a less important role in their location choices. The migration of university graduates is driven primarily by regional differences in wage levels. Comparing with vocational college entrants, regular university entrants are attracted to regions with more national key universities. Comparing with vocational college graduates, regular university graduates are attracted to regions with higher wage levels. Our findings suggest that increasing labor market returns is a more effective approach than investing in higher education to curb brain drain in China’s less developed regions.