An award-winning campaign under the title “Don’t let sleeping coins lie”, the Bundesbank called upon the general public to hand in unused coins hidden in piggy banks, under pillows or among their socks. By November 2001, we had already collected more than 20% of all coins in circulation. Of course, a substantial amount of D-Mark is still in circulation.
In part this more moderate effect reflects increased energy efficiency and other structural changes, but I believe the dominant reason is that the use of constrained discretion in the making of monetary policy has led to better anchoring of inflation expectations in the great majority of industrial countries.