Codes and Frequencies
Most IPUMS data transformations are performed using variable harmonization tables that specify how each value in the source data is recoded. Some variables also require programming logic in addition to the harmonization table. The harmonization documents for this variable are:
MET2013 identifies metro areas of residence 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.
MET2013 is available only for 2000 and later samples. Another variable, METROUS, identifies metro areas for earlier samples. Both variables are available for samples from 2000 through 2010. For more information on MET2013 and METROUS, refer to the IPUMS-USA website.
Comparability — General
MET2013 differs from METROUS in several ways:
- Delineation base year: METROUS uses 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. MET2013 uses only the 2013 OMB delineations.
- County basis: For samples from 1950 through 2011, METROUS uses 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 MET2013 are instead entirely county-based, even in New England.
- Code scheme: METROUS uses 4-digit codes based on 1990 and 1999 OMB codes, but with several adjustments to reflect historical hierarchical relationships among metro areas. MET2013 codes instead use the 5-digit 2013 OMB codes with no adjustments, making it easier to associate MET2013 codes with data from other sources where the OMB codes are used.
- Representativeness: METROUS identifies metro areas only for 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 METROUS). As detailed in the Description section, MET2013 uses an alternative protocol that aims to maximize representativeness. MET2013 also suppresses codes for areas where the sum of omission and commission errors is 15% or more.
- All households
- United States: 2000, 2005, 2010, 2015