In real world terms, the Richmond branch of the Federal Reserve asks 71 firms - I can't easily find who, but they're all in "the District of Columbia, Maryland, North Carolina, South Carolina, Virginia, and most of West Virginia" - something very much like - hey so in the past month, have you been able to hire employees with the skills you need And of those 71 firms surveyed, they take the firms answering "yes" and make that into a percentage, the firms answering "no" and make that into a percentage, then subtract "no" from "yes." So in this case, if 20 of those firms said "yes", that would be 28%. The 51 who said "no" would be 72%. Subtracting 72% from 28% would give you -44%. It's an abstraction? But it's an abstraction they've been chasing since 1993. What I think is awesome is of those 51 who said "no", like 10 of them said "but I totally see this resolving itself on its own in six months." Because they are teh stupid.