Small Area Population Estimates by Demographic Characteristics: A Case Study for 170 Census Tracts in Multnomah County, Oregon

Qian Cai, Portland State University

With an increasing demand for small area population estimates, it calls for both the innovative ways of using existing data and the new techniques that are suitable for small area estimates. This paper is such an attempt. It explores the methods for population estimates by age, sex, race and Hispanic Origin at census tract level for Multnomah County, Oregon. In addition to the commonly-used estimates methods, new techniques were also developed, including using building permits data to estimate the migration component of the census tract population, and the bridged-race methodology to convert the 2000 Census multiple race back to four single races used in the 1990 Census. Since the American Community Survey (ACS) collected data for Multnomah County since1996 when it became nation's one of the first four test sites, the paper also discusses the potentials of using ACS as benchmarks for the demographic characteristics at sub-county level.