Project summary: Children of Immigrants in Mexico and the United States More than half a million U.S.-born children currently live in Mexico. Research has largely overlooked this important population of U.S. citizen children, particularly in comparison with children of immigrants who remain in the United States. This study will provide a detailed socio- demographic portrait of the large binational population of Mexican American children of immigrants living in the United States and in Mexico. Mexican and U.S. census data from 2019- 2020 will be combined and analyzed to describe and compare the socioeconomic conditions faced by children of Mexican immigrants born in Mexico who live in the United States and children of Mexican immigrants born in the United States who live in Mexico. Socioeconomic conditions include family and household structure, child’s enrollment in school, children’s access to health care, and household economic resources. U.S.-born children in Mexico who are there because they accompanied a deported parent will be identified using new questions on the 2020 Mexican Census about the parents’ reason for return to Mexico. The study will estimate the extent to which U.S.-born children in Mexico are there due to de facto deportation and how the socioeconomic conditions they face in Mexico compare to those faced by children at risk of de facto deportation in the United States. The research will give scholars, policymakers, and practitioners up-to-date, valid estimates of the size and characteristics of the large, binational population of Mexican American children of immigrants living in Mexico and the United States.