In Mexican data, “U.S. born” refers only to persons born in the United States and not to the citizenship at birth.
“Return migration” is a concept based on a census or survey question about prior residence, specifically residence five years before the census or survey. A “return migrant” to Mexico is a person who lived outside of Mexico (usually in the U.S.) five years before the census or survey and is back in Mexico at the time of the survey.
“Recent migrants” are identified through a question in Mexican censuses and surveys that asks whether any members of the household have left to go to the U.S. in a prior period, usually the previous five years. The recent migrants may be back in the household or elsewhere in Mexico (in which case they have “returned” to Mexico) or they may still be in the U.S. or in another country.
“U.S.-born residents with Mexican parents” are people born in the United States with either a Mexican-born mother or father. The Mexican data sources do not have a direct question about the country of birth of a person’s mother and father. Consequently, parentage must be inferred from relationships to other members of the household. About 89-91% of U.S.-born children in the Mexican censuses can be linked with one or two Mexican-born parents, about 2% can be linked only with non-Mexican parents, and the remaining 7-9% are in households without either parent.