Two recent employment reports have differed so widely as to suggest to me that either something grossly improbable has happened or that a serious error has been made.
Last Thursday the company ADP, which provides data processing services for over 500,000 companies, published a report that non-farm employment rose by 157,000 jobs in the month of June. The ADP report was based upon a survey of 340,000 companies. That report can be seen here: www.adpemploymentreport.com/PDF/FINAL_Release_June11.pdf
The very next day The Bureau Of Labor Statistics published their report that during June the non-farm employment rose by 18,000 jobs. The BLS report was based upon a survey of 140,000 companies. This report can be seen here: www.bls.gov/news.release/empsit.nr0.htm
The historical agreement over the last 10 years of these two employment estimates can be seen in a graph covering the period of 2005-2010 here: www.adpemploymentreport.com/ner/charting.aspx
Stock markets around the world were buffeted by the two reports, first up on the ADP report and down after the BLS report.
I have tried to make simple models of how ADP and the BLS might have generated these numbers. These models result in a ratio distribution whose parameters are not available, but assuming that the two estimates should be highly correlated and that the width of either distribution is much smaller than the median, I find the discrepancy to be too great to explain by sampling. It seems to me that some serious error has been made.
I invite comments by interested parties in this group.