The ENADID has some limitations when it comes to providing full coverage of migration flows between Mexico and the U.S. All migrants into Mexico in the period before the survey (who are still alive and still in Mexico) can be identified. However, for recent out-migrants, only those migrants from households where some members remained in Mexico can be identified. ENADID is not able to measure outmigration of whole households.
The migrant sample includes only a limited amount of socio-demographic data on the migrants. However, most of the recent migrants who have returned to Mexico (i.e., those who returned to the same household) can be linked to their own record in the household and sociodemographic data. For 2014, we were able to match 90% the returned recent migrants (739 unweighted cases out of 818 returnees in the migrant sample). Because some migrants make multiple trips to the U.S., some of the returned recent migrants (i.e., those who made a trip out of Mexico after August 2009 in 2014) were living in the U.S. five years before the survey. In measuring total migration into Mexico, it is necessary to remove this group from the estimate to avoid double counting. Using the matched samples, 30% of the returned recent migrants in the 2014 ENADID had been in the U.S. five years earlier.
The data from ENADID employed in this report were developed from tabulations of microdata samples. The microdata come from a 93% sample of the full ENADID sample (101,000 households); all cases in the recent migrant sample are included in the microdata. For 2014, microdata samples were downloaded from the INEGI website (entered at
http://www.inegi.org.mx/est/contenidos/proyectos/encuestas/hogares/
especiales/enadid/enadid2014/default.aspx). The sample sizes for the microdata are: 94,422 households, 348,450 people living in those households and a sample of 2,289 recent migrants.