Short-Run and Long-Run Effects of Changes in Money in a Random-Matching Model

A random-matching model of money is used to deduce the effects of a once-for-all change in the quantity of money. It is shown that the change has short-run effects that are predominantly real and long-run effects that are in the direction of being predominantly nominal provided that the change is random and people learn its realization only with a lag. The change in the quantity of money comes about through a random process of discovery that does not permit anyone to deduce the aggregate amount discovered when the change actually occurs