The “Debt Deflation Theory” provided by professor Irving Fisher showed how the efforts of the Central Bank to restart the American economy were not successful during the Great Depression of the 30s. He proposes so as an alternative solution the use of a stamped currency. In this paper we analyze from a
theoretical perspective this proposal, looking at the consequences of the introduction of the demurrage in the Goods Market. Through a practical case we discuss how the stamped money can be introduced in a city and how to handle the problems arising from the reconversion issue. In the last section we analyse the Silvio Gesell’s proposal of completely substituting the national currency with a demurrage, by looking at the effects on the money market model and on the IS LM model.