Introduction to the IPUMS Translation Tables

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Go to Alphabetical Listing of IPUMS Translation Tables

The integration of disparate variable names and coding schemes is one of the most important goals of the IPUMS project. "Translation tables" are the main tool that we use to integrate various coding schemes over time. The basic function of a translation table is to show how codes from the original Public Use Microdata Samples align to codes in the IPUMS files that we make available on this website.

Translation tables have a consistent format. The first two columns of each translation table show the "integrated" IPUMS code and the IPUMS label. Subsequent columns show how values in the original source data correspond to the IPUMS codes.

Each of the columns describing original source data includes cells identifying the sample (e.g. us1940a), record type ("H" or "P"), and variable location in the original data (e.g., column 80). The codes in each column on the right-hand side of the translation table are values from the original source data. Each value in the original source data is aligned in the same row as its integrated IPUMS code in the leftmost column.

If samples from from multiple years share a record layout and coding scheme (as is often the case in the American Community Survey samples), those samples will share a column in the translation table. The same is true when multiple samples exist for a given year (for instance, the 2000 1% and 5% samples): the samples will share a column if they have the same codes and layout; they will have separate columns if they have different codes or layouts.

The list at the bottom of this page shows how samples are identified in the translation tables.

Other details:

  • Some variables do not require any recoding; these are identified with a value of "1" in the table row lablelled "norecode".
  • An asterisk (*) in any cell indicates that for that year cases with the IPUMS value for that row were created by special programming rather than through simple recoding. Sometimes entire variables need to be created via complex programming (rather than simple recodes); in those cases the original column location is listed as "0".
  • A "B" or "BB" or any combination of "B" indicates values in the input data that were left blank.

Below is a modified example of the translation table for the IPUMS variable VETSTAT that demonstrates some of the features of the translation tables.

code label us1940a us1950a us1960a us1970b us1980a us1990a us2000a us2000d us2001a us2002a us2005a us2006a
rectype P P P P P P P P P
columns 164=165 0 80 80 72 72 138 53 60
norecode 1
0 N/A 2 2 * 0
0 Under age 18 18
0 Under age 18 21
0 Under age 18 22
0 Under age 18 28
0 Wife of veteran 23
0 Under age 17 0 B B
0 BB
1 No Service 19 1 1 1 4 4 4 5
1 Now on active duty 1 1 1
1 Training for Reserves or National Guard only 4
2 Yes 29 0 0 0
2 Yes, on active duty in past but not now 2 2 2 2
2 Yes, service in reserves or national guard only 3 3 3 3
9 Unknown 88
9 Not ascertained 89

Original "input" or "source data" samples listed in the translation tables

us1850a: 1850 1% sample us1980a: 1980 5% sample
us1860a: 1860 1% sample us1980b: 1980 1% sample
us1860b: 1860 1% sample with black oversample us1980c: 1980 Urban/Rural sample
us1870a: 1870 1% sample us1980d: 1980 Labor Market Area sample
us1870b: 1870 1% sample with black oversample us1980e: 1980 Detailed metro/non-metro sample
us1880a: 1880 1% sample us1990a: 1990 5% sample
us1900f: 1900 1% sample us1990b: 1990 1% sample
us1900g: 1900 1% sample with oversamples us1990c: 1990 Unweighted 1% sample
us1910i: 1910 1% sample us1970e: 1970 Form 1 Neighborhood sample
us1910j: 1910 1.4% sample with oversamples us1990d: 1990 Elderly sample
us1920a: 1920 1% sample us1990e: 1990 Labor Market Area sample
us1930a: 1930 0.5% sample us2000a: 2000 5% sample
us1940a: 1940 1% sample us2000b: 2000 1% sample
us1950a: 1950 1% sample us2000c: 2000 Unweighted 1% sample
us1960a: 1960 1% sample us2000d: 2000 ACS sample
us1970a: 1970 Form 1 State sample us2001a: 2001 ACS sample
us1970b: 1970 Form 2 State sample us2002a: 2002 ACS sample
us1970c: 1970 Form 1 Metro sample us2003a: 2003 ACS sample
us1970d: 1970 Form 2 Metro sample us2004a: 2004 ACS sample
us1970e: 1970 Form 1 Neighborhood sample us2005a: 2005 ACS sample
us1970f: 1970 Form 2 Neighborhood sample us2006a: 2006 ACS sample