The SIPP 1990-1993 panels collected information about jobs held by each respondent and assigned these jobs identification numbers. Researchers are often interested in following jobs over the time period covered by the panel and have used the job id variables WS12002 and WS22102 from the core wave files to link jobs across SIPP waves. However these job id variables are not always longitudinally consistent. Some job transitions are missed because the same job id continues to be used even after the respondent has switched employers. Other false job transitions are introduced when the job id is changed without a corresponding employer change. Hence accurate measures of job tenure are difficult to calculate using these files.

A research project at the Census Bureau investigated this problem and produced new job id variables to be used with the the core wave files for the 1990-1993 panels. These revised job ids are longitudinally consistent and will allow researchers to more accurately link job information across waves. They were created using confidential employer name information and administrative data containing individual-level job counts. The following document gives the details of the research project, as well as instructions for how to merge the revised job ids to the core wave files.