New techniques for estimating migration

In this paper we analyze migration in one well-known long-running surveillance program, the Agincourt HDSS in South Africa. Migration is a key demographic event for populations monitored with surveillance systems, yet we argue that it is underappreciated in current HDSS practice. We provide (1) analysis of secondary data predicting migration, and hence LTFU; and (2) results from a randomized study of migrant contact and follow-up, testing the efficacy of in-person versus face-to-face interviews in the South African setting. Our results are designed to help researchers and administrators connected to HDSS understand migration dynamics and its potential impact on population and health studies.

Migration data resources in Iran include census, sample studies and administrative data each of which have some limitations: national migration data is generally obtained from censuses. It is conducted every 10 years and doesn’t reflect current trends. International migration data comprises of people who born abroad and live in Iran, but it doesn’t show origin-destination flows, length of migration and mistakenly includes Iranians born abroad who return back to Iran. It also lacks information about people who born in Iran and then emigrates. Sample studies have limitation of covering all migrants unless the survey is carried out in a national level. Administrative data on legal international migrants accompanies limitation of unadjusted travel justifications issued due to changing residential intentions by the use of legal loopholes. In addition, administering organizations are not obligated to publish migration statistics they routinely collect. This paper discusses possible solutions for these limitations on the base of organizational relations in Iran. The study main method is a survey conducted among 530 data migration professionals including practitioners, researchers, experts and university professors. The results are discussed in three sites: migrants entering Iran, movements inside Iran and migrants leaving Iran.

Data on international migration trends are crucially lacking, especially in developing countries. The lack of basic information on migration is in sharp contrast with the increasing importance of migration in the population and development agenda.
Demographic surveys offer unique opportunities to collect original data on international migration. A few simple questions in relatively small-scale surveys can be used to reconstruct migration trends with a reasonable degree of precision, and can greatly improve the knowledge of levels, trends, and patterns of international migration. The objectives of this paper are threefold: (1) To describe the data and method used to reconstruct trends in first departure and returns.
(2) to reconstruct trends in migration in Senegal, Ghana and DR Congo with data from the MAFE project , and (3) to assess the quality of these estimates.

As a consequence of the economic recession in the United States, and many other factors, migration between Mexico and the United States reached a historic point of net migration zero around 2010. Is this a new era or just a pause? The answer to this question is a major challenge for scholars and policy makers. The Border Survey of Mexican Migration (EMIF) offers a unique data set to follow up on labor migration flows from and to the United States. The main objective of this paper is to present EMIF, a unique methodology of labor migration flows. Operating since 1993, EMIF is the oldest continuous research program tracking original data on the number of people crossing the U.S.-Mexico border, whether legally or illegally. The objective of the Border Survey of Mexican Migration is to provide unbiased estimates of the size, composition, and characteristics of Mexican labor flows taking place across the U.S.-Mexico border. The cities and towns along the Mexican side of the U.S.-Mexico border constitute the main migration corridor between the two countries. With more than 90 percent of U.S.-Mexico migration flows passing through the border region, it serves as an ideal observatory.

In a great deal of countries do not have statistical records on international migration and the data they use comes from censuses that are carried out in ten-year intervals which are unable to capture cyclical changes of international migration. The purpose of this paper is to present the methodology of estimation of a new source of information on international migration flows in Colombia which is being developed by the Departamento Administrativo Nacional de Estadística (DANE) and Migración Colombia. This new source consists of individual records of passengers collected at border controls by air, land and sea. With this information, DANE produces an estimate of the international migration flows. The database contains demographic information and geographic information, socioeconomic data and the legal status of travelers. The data used in this study comes from the 41,683,460 international trips registered in the period 2004-2010. The data have been subjected to a process of anonymization so as to allow the reconstruction of individual information on the travel itineraries of 10,461,355 people for the same time period. The methodology and the reconstruction of migration flows (comparing them with those registered in others countries) are some of the aspects discussed in this paper.

Compared with fertility and mortality, comparatively little attention has been given to the way in which internal migration varies between countries around the world. This paper presents results from the IMAGE project, a collaborative international research program which aims to provide a robust framework for systematic comparisons of mobility and advance understanding of cross-national differentials. The paper utilises data from the IMAGE database, a global repository of internal migration data collections, to estimate aggregate migration intensities (all ‘permanent’ changes of address) over one and five year periods for a large sample of UN Member States. We utilise a range of statistical methods to harmonise the data as far as possible for differences in the temporal and spatial frameworks on which the data are collected, and produce a league table ranking countries on overall levels of internal migration. Results reveal marked differences in migration propensities between and within world regions, with relatively low mobility across much of Asia and higher movement intensities in More Developed Countries.

International migration flow data often lacks adequate measurements of volumes, direction and completeness. These pitfalls limit comparative studies of migration and constrain cross national population projections to use net migration measures or inadequate data. This paper aims to address these issues at a global level, presenting estimates of bilateral flow tables between 191 countries. A methodology to estimate flow tables of migration transitions for the globe is illustrated in two parts. First, a methodology to derive flows from sequential stock tables is developed. Second, the methodology is applied to recently released World Bank migration stock tables between 1960 and 2000 (Ozden, 2011), estimating a set of four decadal global migration flow tables. The results of the applied methodology are discussed with reference to comparable estimates of global net migration flows of the United Nations and models for international migration flows. The proposed methodology adds to the limited previous literature on linking migration flows to stocks. The estimated flow tables represent a first-of-a-kind set of comparable global origin-destination flow data.

In this study, we examine age patterns of migration among adults who resided in Seoul in the early 20th century. We use information, obtained from the Seoul household registers, on the length of time these adults lived in their current residences to estimate age-specific migration rates and construct migration life tables. Our findings point to the following: First, Seoul residents were quite mobile. On average, during the early 20th century, Seoul residents moved approximately four times between their primary working ages of 15 and 64. Second, upper-class individuals were more mobile than lower-class individuals. While the upper-class individuals moved approximately five times between ages 15 and 65, the lower-class individuals moved less than three times. This class differential can be explained because Korean bureaucrats experienced frequent duty changes during this period. Third, household composition also affected migration rates. We compare our results with European migration studies and discuss the implications of these finding on urbanization that occurred in early 20th-century Seoul.

This paper investigates the distribution of distance associated with marriage migration in the flood prone area of North-Eastern Bihar, India and an effort has been made to fit some mathematical model to marriage migration associated with distance. The survey was conducted during October 2009 to March 2010 on 664 households and data was collected from 930 married women. A well known mathematical model proposed by Morril & Pits has been applied on the data to check its suitability and a probability model (Weibull distribution) has been used to explain the phenomenon and found that both the model explains distance associated marriage migration.

In India, caste system has strong routes in society and it affects the environment in which migration decision takes place. Since different caste/ religion groups have different impact on migration process thus in the present study an attempt has been made to study the trends in rural out migration at the household level according to different caste/ religion groups. Data have been taken from a survey conducted in the flood prone area of Bihar, India in 2010. Some probability models have been proposed to describe the phenomenon and it has been applied to the observed distribution of migrants from the households. Under certain assumptions, it was found that inflated geometric and beta geometric distributions explain satisfactorily the pattern of migration. Also in this study an attempt has been made to know the distribution of risk of migration which cannot be observed directly.