A Surname-Based Measure of Ethnicity, and Its Applications to Studies of Ethnic Segregation: The Early Twentieth Century U.S.∗ Dafeng Xu† Abstract Many studies consider ethnicity as an equivalent term for the country of birth. This could ne- glect ethnic heterogeneity within the sending country. Focusing on German-born, Polish-born, and Russian-born immigrants in the 1920 and 1930 U.S. census, I propose an ethnicity variable constructed based on the linguistic origin of the surname using an artificial intelligence algorithm. Employing this ethnicity variable, I study ethnic segregation within each immigrant group defined based on the country of birth. Results suggest the degree of within-group ethnic segregation was high. Specifically, ethnic majorities within each immigrant group generally resided in areas with significantly more compatriots. Keywords: immigration, surname, ethnicity, segregation, early twentieth century U.S. JEL Classification: J1, N3, R1 ∗I thank Fran Blau, Nancy Brooks, Jack DeWaard, Marina Gorsuch, Dave Hacker, Larry Kahn, Dan Lichter, Mao-Mei Liu, Matt Nelson, Evan Roberts, Steve Ruggles, Matt Sobek, Tony Smith, Yannay Spitzer, Eddie Telles, Dave Van Riper, Zach Ward, Rob Warren, Klaus Zimmermann, Ariell Zimran, and seminar participants at Cornell University, University of Minnesota, and the 2018 Population Association America (PAA) meeting for their valuable suggestions. I also receive helpful comments from Ran Abramitzky on a highly related project. I thank Joe Grover, Kai Hong, and Jonathan Schroeder for their discussions on data and methodologies in this paper. †225 19th Ave. S., University of Minnesota, Minneapolis, MN 55455. Email:
[email protected]. 1 1 Introduction Many studies in labor, population and regional economics consider ethnicity, or ethnic ori- gin, as the equivalent term for country of birth (e.g., Fairlie and Meyer, 1996; Bleakley and Chin, 2004).