Alejandro Blei has been affiliated with the NYU Urban Expansion Program since 2014 when he joined as research coordinator for the Monitoring Global Urban Expansion Initiative, a collaboration between New York University, UN Habitat, and the Lincoln Institute of Land Policy. In that capacity he oversaw data processes and quality control for Phase I: 2016 Atlas of Urban Expansion – Vol. I Areas and Densities, and Phase III: The Land and Housing Survey in a Global Sample of Cities. In these roles he helped develop metrics and created visualizations that have been used in the Atlas and elsewhere to describe urban expansion patterns over the 1990-2014 period. He is also a co-author of the Atlas of Urban Expansion (2012) where he created a historical dataset of spatial and population changes in a global sample of 30 cities for the 1800-2000 period. That dataset is the basis of a widely viewed collection of urban expansion animations on YouTube. At the Marron Institute, Alex has led research for a variety of projects: inclusive metropolitan economies (Rockefeller Foundation), loss of cultivated land to urban expansion (World Resources Institute), and comparisons of Atlas land cover classifications and urban extent boundaries to the Global Human Settlements Layer (NYU-Lincoln Institute). Prior to joining the Marron Institute he was a National Science Foundation IGERT trainee in transportation science at the University of Illinois at Chicago.  Before that, he was a transit planner in Chicago and New York.