Research Methodology

Based on methods designed to measure periodic, cyclical or seasonal movements employed in other disciplines such as biology, the survey methodology uses an analogy between the movements of migratory species that travel via rivers and the flows of human migrants between countries.

Migration flows tend to concentrate at certain border points where people can cross with or without documentation. At a specific moment, these flows of people become so physically narrow so as to have the width of a door in a bus station. At that point it is possible to quantify the volumes of the flow and characterize the individuals who are travelling, through surveys and statistical methods.

Target Population

At each of Mexico's borders, North and South, the surveys identify migration going both ways, North to South and South to North. In EMIF Norte there are three main flows:

  1. Migrants from the South: individuals 15 years and older, both born in Mexico and residents of Mexico, who do not live in the city where the interview takes place, whose migration to the northern border is motivated by the search for work opportunities, a change in residence, or another reason, and who do not have a planned return date to their usual place of residence.

  2. Migrants from the North: individuals 15 years and older, born in Mexico and residents of either Mexico or the United States, who do not live in the city where the interview takes place, who are leaving the northern border or coming from the United States, whose migration is motivated by the search for work opportunities, a change in residence, or another reason, and only those people whose period of stay has been greater than one month.

  3. Migrants returned by U.S. immigration officials: individuals 15 years and older, born in Mexico and either residents of Mexico or the United States, returned by U.S, immigration officials to Mexican immigration officials.

Within these flows of migration identified in EMIF Norte, target populations are defined according to their final destination (see Diagram 1)



Diagram 1: Travel direction, migration flow and target population in EMIF Norte


For EMIF Sur, migration is characterized by its origin (Guatemala, El Salvador and Honduras), its destination (Mexico or United States) and the return condition (if the person is returned by either United States or Mexican immigration officials). From these combinations, four migration flows are identified and within each of these at least one target population is identified (see Diagram 2).

  1. From Guatemala travelling to Mexico or the United States: individuals not born in the United States or Mexico, coming from Guatemala or another country and who will cross Mexico in search of work opportunities in Mexico or the United States, or will at least stay in one of these countries for a period greater than one month.

  2. From Mexico or the United States heading to Guatemala: individuals not born in the United States or Mexico, coming from one of these two countries, and whose relocation was for work motives or to search for work in those countries, or at least to stay for a period greater than one month. This migration flow includes people who live in one of these two countries and are returning to visit their home country.

  3. Migrants returned by U.S. authorities by airplane: individuals who crossed Mexican territory to arrive to the United States, who declared to have been born in Guatemala, Honduras or El Salvador to immigration authorities, who lived in U.S. territory without the required documentation and were detained and sent back to their country of origin through an international airport.

  4. Migrants who declared to Mexican immigration authorities to have been born in Guatemala, Honduras or El Salvador, who lived in Mexican territory without the required documentation and were detained and sent back via land to their country of origin.



Diagram 2: Travel direction, migration flow and target population in EMIF SUR