Monetary neutrality

A proposition that in the long run, a percentage rise in the money supply is matched by the same percentage rise in the price level, leaving unchanged the real money supply and all other economic variables such as interest rates.

This theory, a core belief of classical economics, was first put forward in the 18th century by David Hume. He set out the classical dichotomy that economic variables come in two varieties, nominal and real, and that the things that influence nominal variables do not necessarily affect the real economy. Today few economists think that pure monetary neutrality exists in the real world, at least in the short run.