Tiit is a professor of Urban and Population Geography and Head of the Centre for Migration and Urban Research at the Department of Geography at the University of Tartu, Estonia. He is a leading scholar on socio-economic and ethnic segregation, urban and neighborhood change, migration, residential mobility and housing. He is especially interested in understanding the spatial dimensions of urban poverty and migration, and associated spatial and social policy. His research interests include migration, residential mobility, housing, ethnic segregation across different life domains (family, neighbourhood of residence, workplace), relations between social inequalities and socioeconomic segregation, as well as comparative segregation studies.