When the smoke and mirrors are set aside, the reality is clear: helicopter money is deficit financing funded by short-term borrowing.

Negative interest rates are the latest in a series of fruitless efforts to revive post-crash economies using monetary policy. Such efforts amount to a distraction from a fundamental truth: The only way to ensure that “new money” is put into circulation is to have the government spend it.

Many have argued that money-financed fiscal expansion shouldn't be ruled out. But talk of such “helicopter drops" has produced counterattacks.