"Funny how they always seem to go ...in ONE direction"Nope."Dont...

"Funny how they always seem to go ...in ONE direction"Nope.

"Dont suppose you have the nous to come up with a theory as to why that might be?"

Who needs a theory when the facts are readily available.

"Revisions

CES-N data are regularly revised on a monthly and annual basis. Less frequent historical data reconstructions or corrections are also possible.

Monthly revisions

CES estimates are considered preliminary when first published each month because not all respondents report their payroll data by the initial release of employment, hours, and earnings. BLS continues to collect payroll data and revises estimates twice before the annual benchmark update (see benchmark revisions section below). For a given month, BLS publishes second preliminary estimates 1 month after the initial release and final sample-based estimates 2 months after the initial release. The estimates published with the second and third (final) releases incorporate additional data from respondents and corrected data. With each new monthly observation and the revisions to previous months’ estimates, BLS recalculates CES seasonal adjustment factors, which also can contribute to revisions in the seasonally adjusted estimates. Tables of the monthly revisions to preliminary CES-N data are available at Nonfarm Payroll Employment: Revisions between over-the-month estimates, 1979–present.

Benchmark revisions

On an annual basis, BLS recalculates nearly 2 years of CES data in a process known as benchmarking. The process corrects for sampling and modeling error by reanchoring sample-based estimates for March of each year to a near complete employment count based primarily on unemployment insurance tax records, which are supplemented with data from other sources. More information about the CES-N benchmark and tables of benchmark revisions to CES-N data are available at Benchmark Information.

Historical corrections and reconstructions

Revisions to CES data are sometimes necessary to correct data or to update to a new industry structure, for example. Most historical reconstructions are incorporated during the next benchmark revision and are detailed in that year’s benchmark article. Archived CES Benchmark Articles and their corresponding tables are available online. Other corrections to historical CES-N data are noted on the BLS Errata Home webpage."

Presentation : Handbook of Methods: U.S. Bureau of Labor Statistics (bls.gov)

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