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Recovered Data

Historic data from thousands of tapes were recovered before the Census Bureau’s Unisys mainframe computer was decommissioned in 2010. Most of these data still need to be developed for research use.

Economic Data

What was Recovered?*

  • A wide variety of Economic (Business) data were recovered from nearly all sectors of the economy, including, Manufacturing, Retail, Services, Wholesale, Mining, Transportation, Construction, Agriculture, and International Trade.

Demographic Data

What was Recovered?*

  • A wide variety of Demographic (people and household) data were recovered, including:
    • Many Current Population Survey supplements (all months)
    • Income Surveys Development Program (forerunner of Survey of Income and Program Participation)

Creating “Usable” Data from the Recovered Data

Converting the Data

  • For technical reasons, the data were typically downloaded from the Unisys in two forms, assuming the data were all in:
    • Excess-3 character set
    • FIELDATA character set
  • If the character set of the underlying data is known, recovered files can be converted to usable formats (e.g., ASCII) through known mappings


  • Data in a record might employ multiple character sets
  • Record layout explaining variables, their lengths, and character set employed may no longer exist or may be incorrect
    • A file showing the first 100 records using 5 different character set assumptions created when the data were downloaded can help reveal variable length and character set
    • Existing microdata and/or published data can help in determining variable content
  • Data files may have other problems such as missing variables or observations, corrupted data, not matching the description in the paper records, etc.

Secure Access to Recovered Data

Step 1: Contact the Recovered Data Team

  • Email the Recovered Data Team the following information:
    • Recovered data of interest
    • Brief description of planned research
    • Whether or not the recovered data is critical to the planned project
  • Recovered data team will respond with basic information about the recovered data of interest

Next Steps

  • If research does not hinge critically on recovered data, submit an RDC project proposal
  • If research does hinge critically on recovered data, request 6–month feasibility access

Interested in these Recovered Data?

Email the Recovered Data Team to learn more.

*A subsequent effort recovered data from additional tapes. Contact the Recovered Data Team for interest in specific surveys and years not in the lists above or among the restricted-use microdata already available to researchers.

Page Last Revised - May 22, 2023
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