You cannot manage anything when the information one is seeing is not correct. The USA data gathering systems are only estimates and extrapolations. Can you imagine what would happen if a CEO of a company was told that the company has “about $10 million of cash available” or “we estimate 2,000 widgets were built” – and this data was given with a 15 day delay and included an estimated error factor.

In the latest case – the employment re-estimate was revised well into the 20th century. Honestly, this gives one less confidence in any employment data even though the revisions were relatively small. From the BLS:

Revisions to Establishment Survey Data

In accordance with annual practice, the establishment survey data released today have been benchmarked to reflect comprehensive counts of payroll jobs for March 2015. These counts are derived principally from the Quarterly Census of Employment and Wages (QCEW), which counts jobs covered by the Unemployment Insurance (UI) tax system. The benchmark process results in revisions to not seasonally adjusted data from April 2014 forward. Seasonally adjusted data from January 2011 forward are subject to revision. In addition, data for some series prior to 2011, both seasonally adjusted and unadjusted, incorporate other revisions.

The total nonfarm employment level for March 2015 was revised downward by 206,000 (-199,000 on a not seasonally adjusted basis, or -0.1 percent). The absolute average benchmark revision over the past 10 years is 0.3 percent.

The effect of these revisions on the underlying trend in nonfarm payroll employment was minor. For example, the over-the-year change in total nonfarm employment for 2015 was revised from 2,650,000 to 2,735,000 (seasonally adjusted). Table A presents revised total nonfarm employment data on a seasonally adjusted basis for January to December 2015.

To get a feel of the benchmark changes:

Change in Seasonally Adjusted Non-Farm Payrolls Between Originally Reported (blue bars) and Current Estimates (red bars)