Demurrage (currency)

Demurrage is the cost associated with owning or holding currency over a given period. It is sometimes referred to as a carrying cost of money. For commodity money such as gold, demurrage is the cost of storing and securing the gold. For paper currency, it can take the form of a periodic tax, such as a stamp tax, on currency holdings. Demurrage is sometimes cited as economically advantageous, usually in the context of complementary currency systems.

While demurrage is a natural feature of private commodity money, it has at various times been deliberately incorporated into currency systems as a disincentive to hoard money and to achieve other perceived benefits. In particular, for long-term investment financing, it affects the dynamics of net present value (NPV) calculations. Demurrage in a currency system reduces discount rates, and thus increases the present value of a long-term investment, and thus gives an incentive for such investments.

Unlike inflation, demurrage gradually reduces only the value of currency held: it functions as a negative interest (a tax) on currency held versus inflation that also reduces the value of savings or retirement funds and increases CPI. A positive interest rate is a subsidy. Both inflation and demurrage reduce the purchasing power of money held over time, but demurrage does so through fixed regular fees, while inflation does it in a variety of ways. Inflation is certainly not always everywhere a monetary phenomenon. Inflation is not always easy to predict & it does not stay fixed through time, but the level of demurrage is fixed by the Government.

Gresham's law that "bad money drives out good" suggests that demurrage fees would mean that a currency would suffer more rapid circulation than competing forms of currency. This led some such as German-Argentine economist Silvio Gesell to propose demurrage as a means of increasing both the velocity of money and overall economic activity.

“Only money that goes out of date like a newspaper, rots like potatoes, rusts like iron, evaporates like ether, is capable of standing the test as an instrument for the exchange of potatoes, newspapers, iron and ether. For such money is not preferred to goods either by the purchaser or the seller. We then part with our goods for money only because we need the money as a means of exchange, not because we expect an advantage from possession of the money. So we must make money worse as a commodity if we wish to make it better as a medium of exchange."

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Wikipedia