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MIGMET131
Metropolitan area of residence 1 year ago (2013 delineations)
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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).

In multi-year ACS/PRCS samples that span different Migration PUMA definitions, this variable is based on whichever Migration 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 Migration PUMA definitions vary within multi-year samples, see the MIGPUMA1 variable description.

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:

2005-2011 ACS and PRCS samples:

2012-2021 ACS and PRCS samples:

  • 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
2022 and later ACS and PRCS samples:

  • 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