Introduction to the 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.
- 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|
|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|
|1||Now on active duty||1||1||1|
|1||Training for Reserves or National Guard only||4|
|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|
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|