The Mexican Family Life Survey (MxFLS) is a broad-purpose nationally-representative longitudinal survey of individuals, their households, families and communities. The MxFLS has been developed and managed by researchers from the Iberoamerican University (UIA, per its name in Spanish) and the Center for Economic Research and Teaching (CIDE, per its name in Spanish) in collaboration with researchers from Duke University and University of California, Los Angeles (UCLA) in the United States. Currently, the MxFLS contains information for a 10-year period, collected in three rounds: 2002, 2005-2006 and 2009-2012. The baseline, conducted in 2002, interviewed over 35,600 individuals living in 8,440 households in 150 communities throughout Mexico. The first follow-up was conducted in 2005-2006 and interviewed 32,400 (91%) of the original respondents along with 6,000 new respondents. The second (MxFLS-2) and third-round (MxFLS-3) were conducted during 2005-2006 and 2009-2012, respectively. Given the longitudinal design of the survey, the MxFLS-2 and MxFLS-3 aimed to relocate and reinterview the sample of the MxFLS-1—including those individuals who migrated within Mexico or emigrated to the United States of America. The MxFLS-2 and MxFLS-3 relocated and reinterviewed almost 90 percent of the original sampled households.

Data Collection
The survey is conducted face-to-face in the home and collects extensive information at the household level including a roster, expenditure and household businesses. In addition, the enumerators administer an instrument to each household member age 12 and older as well as obtaining information on each child in the household from the child’s primary care-taker. Information is collected from each adult on education; work, earnings, income and participation in public programs; assets, and credit; migration within Mexico and outside of Mexico; marriage and child-bearing; non co-resident family and transfers; crime; expectations and preferences. Self-assessed health status, health expectations and use of health services are recorded. One feature of MxFLS is that respondents who move to the United States are followed and interviewed there and, those who return to Mexico, are tracked to their new home. Of the respondents who are known to have moved to the United States between the baseline and first follow-up, 91% were interviewed in the United States.

In each wave of the survey, a physical health assessment is conducted as part of the individual interview. In the baseline, height, weight, waist circumference, hip circumference and blood pressure were measured along with hemoglobin, which was measured in the home with the Hemocue photometer. These measures were repeated in the first and second follow-ups. In the first follow-up, total cholesterol and (nonfasted) glucose were measured in the home. In the second follow-up, sitting height was assessed. In addition, HDL, total cholesterol and, for a sub-sample, HbA1c are measured in the home. HDL and total cholesterol are measured with the CardioChek Analyzer and HbA1c with the Bio-Rad In2It Analyzer. The CRP was measured using blood spots collected in the second follow-up.