Goodhart’s Law states that if you rely on a single measure to set economic policy, it will mislead you. Charles Goodhart coined it in 1975 when he was senior adviser to the Bank of England it was targetting growth in the money supply. It’s taken longer for the law to apply to the Bank’s targetting of inflation through interest rates set by the Monetary Policy Committee, but it’s arrived now.
from Neil Collins:
You may not have heard of Adam Posen, but you hadn't heard of David "Danny" Blanchflower before the banking crisis. Posen is Blanchflower's replacement on the Bank of England's Monetary Policy Committee and, boy, does he have some strong views. Here he is before the US Congress three months ago, with some modest proposals.