Wenfei Xu PhD student in urban Planning at the Graduate School of Architecture, Planning and Presentation at Columbia University, focusing on social-spatial stratification, segregation, race and ethnicity, quantitative methods, and neighborhood change in the United States. Her work is motivated by an interest in the historical legacies of structural inequality and its spatial-temporal manifestations. It has examined the influence of historical redlining on processes of urbanization using causal inference methods. More recently, she has explored the uses of "big data" in characterizing human activity for urban social science research. Wenfei holds dual Masters in Urban Planning and Architecture from MIT and a BA in Economics from the University of Chicago.