Before I explain why the number is questionable, though, a few words about where I’m coming from. Contrary to some of the sound-and-fury last week, I do not work for the Mitt Romney campaign. I am definitely not a surrogate. My wife, Suzy, is not associated with the campaign, either. She worked at Bain Consulting (not Bain Capital) right after business school, in 1988 and 1989, and had no contact with Mr. Romney.
The Obama campaign and its supporters, including bigwigs like David Axelrod and Robert Gibbs, along with several cable TV anchors, would like you to believe that BLS data are handled like the gold in Fort Knox, with gun-carrying guards watching their every move, and highly trained, white-gloved super-agents counting and recounting hourly.
Let’s get real. The unemployment data reported each month are gathered over a one-week period by census workers, by phone in 70% of the cases, and the rest through home visits. In sum, they try to contact 60,000 households, asking a list of questions and recording the responses.
Some questions allow for unambiguous answers, but others less so. For instance, the range for part-time work falls between one hour and 34 hours a week. So, if an out-of-work accountant tells a census worker, “I got one baby-sitting job this week just to cover my kid’s bus fare, but I haven’t been able to find anything else,” that could be recorded as being employed part-time.
The possibility of subjectivity creeping into the process is so pervasive that the BLS’s own “Handbook of Methods” has a full page explaining the limitations of its data, including how non-sampling errors get made, from “misinterpretation of the questions” to “errors made in the estimations of missing data.”
Bottom line: To suggest that the input to the BLS data-collection system is precise and bias-free is—well, let’s just say, overstated.