Cities

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Overview

The CITY variable identifies the city of residence for households located in identifiable cities. The identified cities are generally consistent with U.S. Census "place" definitions. For an explanation and history of the concept, see Chapter 9 in the Census Bureau's Geographic Areas Reference Manual. This page provides information about identified cities and their correspondence to Public Use Microdata Areas (PUMAs).

PUMAs are the only sub-state-level geographic area identified in public-use microdata samples from decennial censuses and the ACS/PRCS since 1990. PUMAs are sometimes coterminous with city boundaries, but they also frequently encompass multiple cities and occasionally straddle city boundaries. Therefore, for most cities, and even for some very large cities, it is impossible to identify the exact set of corresponding PUMS records. The protocol used for the CITY variable in 1990 and later samples is to identify the city in which the majority of each PUMA's population resided. Where a city is identified, it indicates that, for the PUMA in which the household resided, a majority of the PUMA's population resided in the identified city, according to population counts from the reference census for the PUMA definitions (e.g., 2000 populations for 2000 PUMAs). A household might not in fact have resided in its identified city, but given its PUMA's population distribution, it is likely that the household resided in the city. See the CITY variable description for complete details on the identification approach.

CITY's code assignment protocol yields errors of omission (residents of a city who are not identified as residents) and errors of commission (non-residents who are identified as residents). CITY reports no code for cities where the sum of match errors is 10% or more.

The crosswalks provided here describe all spatial associations between cities and PUMAs, including the population in each area of intersection. The match summaries identify the best-matching set of PUMAs for each city (i.e., the PUMAs where a majority of population resides in the city) along with omission and commission errors. Match summaries are provided for all cities, including those that exceed CITY's 10% mismatch limit.

Large Place-PUMA Crosswalks and Match Summaries

For census samples, CITY identification is based on the PUMAs, place definitions, and population counts associated with the corresponding census. For ACS and PRCS samples, CITY identification is based on census information corresponding to the PUMA definitions used in the source samples, as follows:

For more detailed information about PUMA-city relationships and CITY match errors, IPUMS provides these tables (in Excel spreadsheets) summarizing relationships between PUMAs and "large" places, defined here as places with populations exceeding 75,000:

2022-2031 ACS and PRCS samples:

2010 10% sample and 2012-2021 ACS and PRCS samples:

2000 5% sample and 2005-2011 ACS and PRCS samples:

2000 1% sample:

1990 5% State sample:

1990 1% Metro sample:

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