title: Interpolating U.S. Decennial Census Tract Data from as Early as 1970 to 2010: A Longtitudinal Tract Database.
abstract: Differences in the reporting units of data from diverse sources and changes in units over time are common obstacles to analysis of areal data. We compare common approaches to this problem in the context of changes over time in the boundaries of U.S. census tracts. In every decennial census many tracts are split, consolidated, or changed in other ways from the previous boundaries to reflect population growth or decline. We examine two interpolation methods to create a bridge between years, one that relies only on areal weighting and another that also introduces population weights. Results demonstrate that these approaches produce substantially different estimates for variables that involve population counts, but they have a high degree of convergence for variables defined as rates or averages. Finally the paper describes the Longitudinal Tract Data Base (LTDB), through which we are making available public-use tools to implement these methods to create estimates within 2010 tract boundaries for any tract-level data (from the census or other sources) that are available for prior years as early as 1970.
authors.affiliation: Department of Sociology and Director of the Initiative on Spatial Structures in the Social Sciences at Brown University, Providence, RI 02912. john_logan@brown.edu . His research focuses on urban development in the U.S. and China, incorporation of immigrants and minorities, and spatial inequalities.
authors.forename: John R
authors.initials: JR
authors.lastname: Logan
authors.affiliation: Department of Geography, University of Wisconsin, Milwaukee, WI 53211. xuz@uwm.edu . His research integrates GIS, complex networks/systems science, and spatial and statistical analyses.
authors.forename: Zengwang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Criminology and Criminal Justice at Florida State University, Tallahassee, FL 32306. bstults@fsu.edu . He studies the relationships between neighborhoods, race, and crime with particular attention to impacts of racial segregation.
authors.forename: Brian
authors.initials: B
authors.lastname: Stults
keywords: 2010 Census; areal interpolation; census geography; census tract; population interpolation