But the methodology is a lot more interesting than the as-expected result. The team followed air fresheners at 16 Wal-Marts for 23 weeks where "a national inventory-auditing group determined each day's on-hand air-freshener inventory by manually counting every item in all 16 stores." Read this RFID Journal piece for a look into how to prove inventory accuracy and why a retailer can never afford to duplicate this study.
Wal--Mart Study Shows 13 Percent Inventory Accuracy Boost With RFID
This is one of these "everyone already pretty much knew this but it's nice someone took the time to prove it" studies. The University of Arkansas was paid by Wal--Mart to find out whether RFID actually improves inventory accuracy. It found that, yes, it does, to the tune of some 13 percent.