Description

For respondents who lived in a different residence 1 year before the survey date, MIGMET131 identifies the metropolitan area where the respondent lived at that time if the prior residence was in an identifiable metropolitan area.

A metropolitan area, or metro area, is a region consisting of a large urban core together with surrounding communities that have a high degree of economic and social integration with the urban core.

MIGMET131 identifies metro areas using the 2013 definitions for metropolitan statistical areas (MSAs) from the U.S. Office of Management and Budget (OMB). The 2013 MSAs are the first to be based on 2010 standards and 2010 census data.

The metro area delineations and codes used by MIGMET131 are consistent with those used by MIGMET135, which identifies the metro area of residence five years ago for decennial census samples.

Note that the 00000 code applies to individuals who lived in the same residence 1 year ago as well as those whose previous residence was not in an identifiable metro area. Users who wish to distinguish these two conditions should use MIGRATE1 in conjunction with MIGMET131.

Inexact Correspondence with Official Delineations
IPUMS determines MIGMET131 codes based on Migration PUMAs (MIGPUMA1).

Because Migration PUMAs occasionally straddle official 2013 MSA boundaries, MIGMET131 cannot identify the exact set of households residing in each metro area.

The protocol IPUMS uses for MIGMET131 is to identify the MSA in which the majority of each Migration PUMA's population resided. If MIGMET131 identifies a metro area for a given respondent, it indicates that, for the Migration PUMA in which the respondent previously resided, a majority of the population resided in the identified metro area.

Match Errors and Code Suppression
MIGMET131's code assignment protocol yields errors of omission (residents of a metro area who are not identified as residents) and errors of commission (non-residents who are identified as residents). Migration PUMAs often nest within MSA boundaries, resulting in small match errors. For many metro areas, however, especially smaller metro areas, the Migration PUMAs are a poor match.

As an index of mismatch, IPUMS uses the sum of percent omission error (the portion of an MSA's population residing in excluded PUMAs) and percent commission error (the portion of the population in associated PUMAs that did not reside in the MSA).

MIGMET131 reports no code for MSAs where the sum of match errors is 15% or more.

For each reported MIGMET131 code, the MIGMET13ERR variable identifies the level of the sum of errors. Researchers may use MIGMET13ERR to impose a more restrictive error limit if desired.

To compute match errors, IPUMS uses 2020 populations for 2022-onward ACS and PRCS samples and 2010 populations are used for 2012-2021 ACS and PRCS samples. For samples that use 2000 Migration PUMA definitions (ACS and PRCS samples through 2011), IPUMS estimates the populations of the areas of intersection between 2000 Migration PUMAs and 2013 MSAs by summing the populations of census blocks that had their geographic center in each area.

For more detailed information about relationships between Migration PUMAs and MSAs and about MIGMET131 match errors, IPUMS provides these tables (in Excel spreadsheets):

2000 5% sample:

• Crosswalk Between 2013 MSAs and 2000 Migration PUMAs

• MIGMET135 Omission and Commission Errors by MSA

• Crosswalk Between 2013 MSAs and 2000 Migration PUMAs

• MIGMET131 Omission and Commission Errors by MSA, 2005-2011

• Crosswalk Between 2013 MSAs and 2010 Migration (and Place of Work) PUMAs

• MIGMET131 (and PWMET13) Omission and Commission Errors by MSA, 2012-2021

• 2010 Migration PUMAs are identical to 2010 Place of Work PUMAs, so these reference files pertain to both MIGMET131 and PWMET13 for 2012-2021 samples

• Crosswalk Between 2013 MSAs and 2020 Migration (and Place of Work) PUMAs

• MIGMET131 (and PWMET13) Omission and Commission Errors by MSA, 2022-forward

• 2020 Migration PUMAs are identical to 2020 Place of Work PUMAs, so these reference files pertain to both MIGMET131 and PWMET13 for 2022 and later samples

Comparability

MIGMET131 is available only for ACS and PRCS samples. For the 2005-2011 samples, another variable, MIGMET1, identifies previous metro area of residence using older metro area delineations and a different coding scheme. For earlier decennial census samples, the metro area of previous residence is identified by the MIGMET5 and MIGMET135 variables.

MIGMET131 and MIGMET135 differ from MIGMET1 and MIGMET5 in several ways:

• Delineation base year: MIGMET1 and MIGMET5 use different metro area delineations for different samples, generally following the delineations in use at the time of each decennial census and following the 1999 OMB delineations for all ACS and PRCS samples through 2011. The MIGMET13 variables use only the 2013 OMB delineations.
• County basis: For samples from 1950 through 2011, MIGMET1 and MIGMET5 use OMB delineations that are county-based, defining each metro area as a set of one or more contiguous counties, except in New England, where each metro area is defined as a set of cities or towns. The 2013 delineations used by MIGMET13 variables are instead entirely county-based, even in New England.
• Code scheme: MIGMET1 and MIGMET5 use 4-digit codes based on 1990 and 1999 OMB codes, but with several adjustments to reflect historical hierarchical relationships among metro areas. The MIGMET13 variables instead use the 5-digit 2013 OMB codes with no adjustments, making it easier to associate MIGMET13 codes with data from other sources where the OMB codes are used.
• Representativeness: MIGMET1 and MIGMET5 identify metro areas only for previous residents of areas that lie entirely within a single metro area, which prevents errors of commission (no non-residents of a metro area are identified as residents), but it puts no limit on errors of omission (sizable portions of many metro areas' populations are not identified by MIGMET1 and MIGMET5). The MIGMET13 variables instead use a majority-assignment protocol that aims to maximize representativeness. MIGMET13 also suppresses codes for areas where the sum of omission and commission errors is 15% or more.
• Error reporting: IPUMS does not currently supply a summary of the omission errors in MIGMET1 and MIGMET5 identifications. For the MIGMET13 variables, IPUMS supplies a separate variable, MIGMET13ERR, that indicates the combined omission and commission error by metro area.

Universe

Availability

• 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: ACS; ACS 3yr; ACS 5yr
• 2009: All samples
• 2008: All samples
• 2007: All samples
• 2006: All samples
• 2005: All samples
• 2004: --
• 2003: --
• 2002: --
• 2001: --
• 2000: --
• 1990: --
• 1980: --
• 1970: --
• 1960: --
• 1950: --
• 1940: --
• 1930: --
• 1920: --
• 1910: --
• 1900: --
• 1880: --
• 1870: --
• 1860: --
• 1850: --

• 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: PRCS; PRCS 3yr; PRCS 5yr
• 2009: All samples
• 2008: All samples
• 2007: All samples
• 2006: All samples
• 2005: All samples
• 2000: --
• 1990: --
• 1980: --
• 1970: --
• 1930: --
• 1920: --
• 1910: --

Flags

Editing Procedure

There is no editing procedure available for this variable.