Description

METRO indicates whether the household resided within a metropolitan area and, for households in metropolitan areas, whether the household resided within or outside of a central/principal city.

In many public-use microdata samples, metropolitan and central/principal-city status are not directly identified. In such cases, IPUMS derives METRO codes based on other available geographic information, e.g., county groups (CNTYGP97 and CNTYGP98) or Public Use Microdata Areas (PUMA). If a county group or PUMA lies only partially within metropolitan areas or central/principal cities, then METRO indicates that the status is "indeterminable (mixed)."

Comparability

While METRO uses consistent codes for all years, the comparability of the variable is limited by two factors:

First, definitions of metropolitan areas and central/principal cities have changed from census to census.

• See METAREA for a detailed discussion of changes in metropolitan area definitions.

• The term "central city" was retired by the OMB in 2003 and replaced with the term "principal city." The term was changed to alleviate confusion as "central city" can connote "inner city", but the OMB definitions do not capture that concept. The definition of "principal city" was also broadened to include census designated places as well as incorporated places.

Since 1940, confidentiality requirements have limited the METRO detail for some households. Although the confidentiality requirements were lifted from the 1940 data in 2012, they were still in effect at the time IPUMS constructed METRO for 1940. The following year-by-year discussion summarizes the confidentiality and sampling issues.

• 1850-1930 samples and 1940 full count: There are no confidentiality requirements. The metro/non-metro and central city distinctions are made for all households.

• 1940 and 1950 1% samples: The metro/non-metro distinction is indicated for all households, even for those in metropolitan areas too small to be identified by name in METAREA. A household's central city status was reported only if the central city (or cities) and the remainder of the metropolitan area each exceeded 100,000 residents in 1980. For interstate metropolitan areas, these criteria were applied separately to each portion of the metropolitan area within a particular state. Households in metropolitan areas not meeting these criteria are classified as "In metropolitan area, central city status indeterminable." IPUMS retroactively identified a number of metropolitan areas that did not meet the necessary criteria for metropolitan status in 1940, but that had been labeled metropolitan areas in the original 1940 PUMS. In IPUMS USA, such areas are coded non-metropolitan in METRO. (See the METAREA variable description for further discussion of 1940 metropolitan area determinations.)

• 1960 1% and 1970 samples: The samples are designed so that no geographic area containing fewer than 250,000 residents can be identified directly or indirectly. As applied to METRO, this meant that metro and central city status could not be revealed for households in the entire 1970 Metro samples and for the following states or state portions in the 1960 sample and the 1970 State samples; households in these areas are all coded 0 ("Not identifiable") in METRO. METRO is available for the 1970 Puerto Rican state sample.

• 1960 1%: Metropolitan and central city status is not available for the entire states of Arizona, Colorado, Delaware, Hawaii, Maine, Mississippi, Montana, Nevada, New Hampshire, New Mexico, North Dakota, Rhode Island, South Dakota, and Utah; plus the rural parts of Arkansas, Iowa, Kansas, Kentucky, Louisiana, Minnesota, Missouri, Montana, Nebraska, Oklahoma, Oregon, West Virginia, Wisconsin; plus the urban part of Maryland.

• 1970: metropolitan and central city status is available for households in the State samples except for those located in the entire states of Arizona, Delaware, Hawaii, Idaho, Maine, Montana, Nevada, New Hampshire, North Dakota, Rhode Island, South Dakota, and Utah; plus the rural parts of Arkansas, Colorado, Iowa, Kansas, Kentucky, Louisiana, Minnesota, Mississippi, Nebraska, New Mexico, Oklahoma, Oregon, West Virginia; plus the urban parts of Connecticut and Maryland. Metropolitan and central city status is not available for households in the 1970 Metro samples.

• 1980: Metropolitan and central city status is specified for all households in the Metro sample. This status is not identifiable for some households in the State sample because that sample's geographical scheme does not always follow Standard Metropolitan Statistical Area lines.

• 1990: The metro/nonmetro distinction and central city status is specified for almost all households in the Metro sample. METRO is a recode of PUMATYPE, which classifies some PUMAs in the Metro sample to be mixed metro/nonmetro. IPUMS assigns households in these PUMAs to have METRO codes of "Metropolitan status indeterminable (mixed)". Metro/nonmetro distinctions are not made for households in the State sample.

• 2000: The 1-percent sample is designed so that no geographic unit containing fewer than 400,000 people can be identified (see PUMASUPR). For this sample, METRO is derived from the variable PUMATY00. Because of the large population threshold, central city status is unknown for most cases in metropolitan areas.

• 2005-2011 ACS: The low-level geography in the 2005-2011 ACS was the PUMA, which had the exact same boundaries as the PUMAs in the 2000 Census data. For these samples, METRO is based on metropolitan area and central city definitions from 2000. This is consistent with the metropolitan area definitions used for METAREA. METRO is not available for the 2005-onward PRCS.

• 2012-2021 ACS: As with previous ACS samples, the low-level geography in these samples was the PUMA, but the 2012 ACS was the first sample to use the 2010 version of PUMAs. For these samples, METRO is based on 2013 OMB (Office of Management and Budget) metropolitan area and principal city definitions. This is consistent with the metropolitan area definitions used for MET2013.

• 2022-2031 ACS: The 2022 ACS was the first sample to use the 2020 version of PUMAs. For these samples, METRO is based on 2023 OMB (Office of Management and Budget) metropolitan area and principal city definitions. This is consistent with the metropolitan area definitions used for MET2023.

Beginning with 2010 PUMA definitions, new standards required that PUMA boundaries follow county or census tract boundaries, which resulted in a great increase in the number of PUMAs that straddle principal city boundaries. Many PUMAs nevertheless lie almost entirely within or outside of principal cities. Rather than assign an "indeterminable (mixed)" status to all these PUMAs, METRO uses a 1% population tolerance for the principal city status of 2010 and 2020 PUMAs. PUMAs with over 99% of population in principal cities are coded as "In central/principal city," and PUMAs with under 1% of population in principal cities are coded as "Not in metropolitan area".

In multi-year ACS/PRCS samples that span different PUMA definitions, this variable is based on whichever PUMA definition is associated with the respondent's survey year (as given by MULTYEAR). This occurs only in the 2022 5-year samples and in multi-year samples that include both 2011 and 2012 survey years. For more information about how PUMA definitions vary within multi-year samples, see the PUMA variable description.

Universe

Availability

• 2023: All samples
• 2022: All samples
• 2021: All samples
• 2020: All samples
• 2019: All samples
• 2018: All samples
• 2017: All samples
• 2016: All samples
• 2015: All samples
• 2014: All samples
• 2013: All samples
• 2012: All samples
• 2011: All samples
• 2010: All samples
• 2009: All samples
• 2008: All samples
• 2007: All samples
• 2006: All samples
• 2005: All samples
• 2004: --
• 2003: --
• 2002: --
• 2001: --
• 2000: 5%; 1% old; 1% unwt; 1%
• 1990: 1% metro
• 1980: 5% state; 1% metro
• 1970: 1% state fm1; 1% state fm2
• 1960: All samples
• 1950: 1%
• 1940: All samples
• 1930: All samples
• 1920: All samples
• 1910: All samples
• 1900: All samples
• 1880: All samples
• 1870: All samples
• 1860: All samples
• 1850: All samples

• 2023: PRCS
• 2022: PRCS
• 2021: PRCS
• 2020: --
• 2019: PRCS
• 2018: PRCS
• 2017: PRCS
• 2016: PRCS
• 2015: PRCS
• 2014: PRCS
• 2013: PRCS
• 2012: PRCS
• 2011: --
• 2010: --
• 2009: --
• 2008: --
• 2007: --
• 2006: --
• 2005: --
• 2000: All samples
• 1990: PR 1%
• 1980: All samples
• 1970: PR 5% state
• 1930: --
• 1920: --
• 1910: --

Flags

Editing Procedure

There is no editing procedure available for this variable.