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Last word: BLS Decennial Census Adjustment
Posted By Barry Ritholtz On February 7, 2012 @ 6:45 am In Data Analysis,Employment,Really, really bad calls,UnGuru | Comments Disabled
Yesterday, I went into some detail  as to why a few people got the NFP data so (disingenuously) wrong. Then Invictus  pointed me to this Economic Populist  post, titled, Getting It Wrong on the BLS Employment Report . It came out late on Friday, hence why it may have been overlooked.
The long term chart via FRED shows the impact the Census has every 10 years on the civilian population. As you can see in the first chart below, this baseline adjustment to population is about 25% larger than 1989′s, but 35% smaller than 1999′s:
The next chart shows the BLS annual population benchmark to make sure their models reflect the latest estimates of population size, growth and characteristics. Note the monthly change between December and January every year — that is the yearly population adjustments.
These are not month-over-month changes, they reflect the adjustments made for the prior year showing up all at once in the month of January.
Hence, to quote the Economic Populist , “it is statistically invalid to compare December to January monthly changes. You simply cannot compare a change of a month, when one of those month’s includes a year of population adjustments.”
Anyone who thinks that 1.2 million people suddenly dropped out of the labor force needs to take a basic statistics course. I wont hold my breath waiting for the usual suspects to admit their errors.
Getting It Wrong on the BLS Employment Report 
Economic Populist Fri, 02/03/2012 – 21:46,
Article printed from The Big Picture: http://www.ritholtz.com/blog
URL to article: http://www.ritholtz.com/blog/2012/02/last-word-bls-decennial-census-adjustment/
URLs in this post:
 some detail: http://www.ritholtz.com/blog/2012/02/a-few-thoughts-on-the-employment-situation/
 Invictus: https://twitter.com/#!/TBPInvictus
 Economic Populist: http://www.economicpopulist.org
 Getting It Wrong on the BLS Employment Report: http://www.economicpopulist.org/content/getting-it-wrong-bls-employment-report
 Image: http://www.ritholtz.com/blog/wp-content/uploads/2012/02/noninstitutionalpopmonthlychg.png
 Economic Populist: http://www.economicpopulist.org/
 Image: http://www.ritholtz.com/blog/wp-content/uploads/2012/02/chgpopmonth.png
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