Editorial

On behalf of the editorial committee of this special edition of the Migration and Health Research Program (Programa de Investigación en Migración y Salud or PIMSA, for its Spanish acronym), the Mexico's Ministry of Health (SSa), the National Council of Science and Technology of Mexico (Conacyt), the Health Initiative of the Americas (HIA) at the School of Public Health of the University of California at Berkeley, and The University of Texas at El Paso, we are pleased to introduce this special publication on migration and health between Mexico and the United States.

Migrant health is a crucial issue for the public health sector of both countries. In the US, 33 million people are of Mexican origin, and this population is experiencing rapid and dynamic growth. Of those, 12 million are immigrants, representing about 30% of the country's immigrant population. Statistics show that the Mexican immigrant and Mexican-American populations in the US are at a disadvantage in terms of health coverage and access to health services with respect to the general population. Research indicates that, despite this disadvantage, Mexican immigrants are in good health, though health disparities emerge as their length of residence in the United States increases. There is a tendency for health to deteriorate over time as immigrants assimilate. In Mexico, since the early 1970s, the traditional Mexico-United States migration pattern has been transformed in magnitude, intensity, modalities, and characteristics. For instance, less than 90 of Mexico's 2 443 municipalities registered no migratory population destined to the United States.

In this context, until recently there was limited research dedicated to understanding the pathways through which migration—as a social, cultural and economic phenomenon—influences health. Currently, appropriate conceptual frameworks and study designs for researching migrant health—dependent on characteristics of definition and measurement—are being developed. Migration is particularly difficult to measure, given that it is a dynamic process that encompasses different stages and population groups: immigrants, emigrants, second generations, and beyond. The determinants and consequences of migration in terms of health are thus relevant to the migrants themselves, their communities and resources in the host country and in countries of origin and transit, and their offspring and future generations.

This special supplement is made up of nine original manuscripts resulting from the work of scholars from both Mexico and the US. Research projects took place within the framework of PIMSA. Given the character of the program, which aims to promote binational collaboration of researchers on issues relevant to migrant health, this supplement contains multidisciplinary contributions in both Spanish and English. It is hoped that this publication will help further the cause of informing public policy through evidence-based research that is timely and relevant to the key concerns of contemporary society.

These nine articles included issues relevant to the health seeking behaviours and health service use of Mexican immigrants in the United States. For example, the determinants of transnational health service utilization; potential policy approaches for expanding access to health care for undocumented immigrants; and the use of binational health insurance plans are among the issues considered here. Articles also relate to the cultural and economic influences of health experiences of migrants and their dependents in Mexico. A research of the use of remittances for health care costs of migrants' dependents and a study of perceptions of overweight among Mexican-American men and Mexican men in Mexico are included.

Throughout the studies presented, this volume brings important findings to light that will serve to improve the health and wellbeing of Mexican immigrants and the Mexican-American population in the United States, as well as that of return migrants, and the families and communities of migrants in Mexico.

PIMSA funds binational research teams whose research proposals focus on migration and health within current policy contexts. Both preliminary and final results of these projects have been presented in public policy forums attended by academic researchers, key stakeholders, and policy makers from Mexico and the United States. Many of these projects have subsequently obtained follow-up funding to continue their research. The results of these projects have been disseminated as public policy documents directed to decision-makers and the media.

PIMSA participating institutions:

• Mexico's Ministry of Health (SSa)

• National Council on Science and Technology of Mexico (Conacyt)

• Universidad Nacional Autónoma de México (UNAM)

• University of California (all campuses)

• California State University (all campuses)

• University of Arizona

• University of New Mexico

• The University of Texas at El Paso

PIMSA is administered jointly by the Health Initiative of the Americas (HIA) and the California Program on Access to Care (CPAC) under the auspices of the University of California, Berkeley, and School of Public Health.

The current volume has been sponsored with the auspices of the Mexico's Ministry of Health and Conacyt.

Xóchitl Castañeda*

* Health Initiative of the Americas, School of Public Health, University of California, Berkeley. US