Reader Tom argues that economic discourse should not include discussion of variables that are unobservable, to wit (or at least indicate that it’s an estimate):
You announce somebody’s estimations of a theoretical, unobservable phenomenon as “the output gap” or “the actual output gap” as if you and they actually know them to be the output gap.
If we used this criterion, what variables would be ruled out from polite conversation? A lot…let’s just take the real interest rate.