Helicopter Money: Irredeemable Fiat Money and the Liquidity Trap

The Paper provides a formalization of the monetary economics folk proposition that government fiat money is an asset of the holder (the private sector) but not a liability of the issuer (the state). Money is 'net wealth' in the limited sense that, after consolidation of the intertemporal budget constraints of the private and public sectors, the present value of the terminal money stock remains a component of comprehensive household wealth. The issuance of irredeemable fiat money can therefore affect consumption demand through a weak 'real balance or Pigou effect', if it can alter the present value of the terminal stock of money. With irredeemable fiat money, weak restrictions on the monetary policy rule suffice to rule out liquidity trap equilibria (that is, equilibria in which all current and future short nominal interest rates are at their lower bound) that are also rational expectations equilibria. Liquidity trap equilibria that are not (long run) rational expectations equilibria can exist if and for as long as the private sector has incorrect but irrefutable expectations that the monetary authorities will ultimately reverse, in present value, any current expansion of the monetary base. If 'quantitative easing' is never reversed, in present value terms, and never expected to be reversed, liquidity trap equilibria cannot occur.