Big Data and Big Cities: The Promises and Limitations of Improved Measures of Urban Life

New, “big data” sources allow measurement of city characteristics and outcome variables at higher collection frequencies and more granular geographic scales than ever before. However, big data will not solve large urban social science questions on its own. Big urban data has the most value for the study of cities when it allows measurement of the previously opaque, or when it can be coupled with exogenous shocks to people or place. We describe a number of new urban data sources and illustrate how they can be used to improve the study and function of cities. We first show how Google Street View images can be used to predict income in New York City, suggesting that similar imagery data can be used to map wealth and poverty in previously unmeasured areas of the developing world. We then discuss how survey techniques can be improved to better measure willingness to pay for urban amenities. Finally, we explain how Internet data is being used to improve the quality of city services. Department of Economics, Harvard University. John F. Kennedy School of Government, Harvard University. National Bureau of Economic Research. Harvard Society of Fellows, Center of Mathematical Sciences and Applications, Center for Research on Computation and Society, and Program for Evolutionary Dynamics. Harvard Business School. MIT Media Lab. We would like to acknowledge helpful comments from Andy Caplin, William Kominers, and Mitchell Weiss. E.L.G. acknowledges support from the Taubman Center for State and Local Government; S.D.K. acknowledges support from the National Science Foundation (grants CCF-1216095 and SES-1459912), the Harvard Milton Fund, the Wu Fund for Big Data Analysis, and the Human Capital and Economic Opportunity Working Group (HCEO) sponsored by the Institute for New Economic Thinking (INET); and N.N. acknowledges support from The MIT Media Lab consortia. Comments are welcome and may be sent to [email protected], [email protected], [email protected], and [email protected].