Open Access
December 2009 Incompatibility of trends in multi-year estimates from the American Community Survey
Tucker McElroy
Ann. Appl. Stat. 3(4): 1493-1504 (December 2009). DOI: 10.1214/09-AOAS259


The American Community Survey (ACS) provides one-year (1y), three-year (3y) and five-year (5y) multi-year estimates (MYEs) of various demographic and economic variables for each “community,” although the 1y and 3y may not be available for communities with a small population. These survey estimates are not truly measuring the same quantities, since they each cover different time spans. Using some simplistic models, we demonstrate that comparing different period-length MYEs results in spurious conclusions about trend movements. A simple method utilizing weighted averages is presented that reduces the bias inherent in comparing trends of different MYEs. These weighted averages are nonparametric, require only a short span of data, and are designed to preserve polynomial characteristics of the time series that are relevant for trends. The basic method, which only requires polynomial algebra, is outlined and applied to ACS data. In some cases there is an improvement to comparability, although a final verdict must await additional ACS data. We draw the conclusion that MYE data is not comparable across different periods.


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Tucker McElroy. "Incompatibility of trends in multi-year estimates from the American Community Survey." Ann. Appl. Stat. 3 (4) 1493 - 1504, December 2009.


Published: December 2009
First available in Project Euclid: 1 March 2010

zbMATH: 1185.62199
MathSciNet: MR2752143
Digital Object Identifier: 10.1214/09-AOAS259

Keywords: Filtering , nonstationary time series , weighted averages

Rights: Copyright © 2009 Institute of Mathematical Statistics

Vol.3 • No. 4 • December 2009
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