is an internationally known scholar of immigration and refugee movements, and has authored more than 150 scientific publications on topics that include:  international migrants and their contexts of exit and reception; social mobility and inequality; transitions to adulthood; intergenerational differences among children, youth and families; educational achievement and aspirations; bilingualism and language loss; ethnic identity, citizenship and national membership; depression, self-esteem, and mental health; and infant health and mortality.  He has served on the editorial boards of the American Journal of Sociology, International Migration Review, Sociology of Education, The Sociological Quarterly, Sociological Perspectives, Journal of Immigrant Health, and Contexts.  With Alex Portes, he led the landmark Children of Immigrants Longitudinal Study (CILS), begun in 1991, and served as the P.I. of the Immigration and Intergenerational Mobility in Metropolitan Los Angeles (IIMMLA) study.  He is the founding chair of ASA’s Section on International Migration, and is a member of the Committee on Population of the National Academy of Sciences.  He received his Ph.D. from Brandeis University.