Cross-checking values for ACS 2015 IPUMS against FactFinder for California and Arizona I found large discrepancies in the OCC2010 values. I used both downloaded OCC2010 and the SDA tool to make sure it was not operator error. These exceed what I would expect because of the relatively smaller sample size of IPUMS vs. the full ACS.
architecture and engineering – FactFinder: 379,146; IPUMS: 434,540
Legal – FactFinder: 211,828; IPUMS: 250,572
FactFinder lists a total of 18,045,450 in the civilian labor force. If you subtract military and “no occupation” from the IPUMS numbers, you get 22,149,745.
I found a similar problem with Arizona – an ACS civilian labor force of 2,937,510 and an IPUMS-derived civilian labor force of 3,730,522.
What puzzles me is that in checking other IPUMS values, such as nativity and citizenship, they have consistently matched or approached those that I have found in ACS with allowance for the smaller sample size. Is OCC2010 the wrong measure, or should I be using a different guidepost to check my results?