[khuey]

Yes, the point is to get you to convert the currency into something that doesn't decay. That keeps the money supply flowing and encourages you to invest in productive assets, both of which are good for society. A deflationary currency encourages you to stuff all your coins under your mattress.

[aethertap]

How does it improve the situation if I'm just buying something else to stuff under my mattress (e.g. silver)? I guess my issue is that it seems like even with a system like this implemented at a national scale, over the long run you'd end up with people rushing to convert the currency into "real" money, that being whatever commodity people land on as being most easily traded/stored/etc. At that point it seems like the commodity becomes the currency.

[maaku]

Because the assets you're holding under your mattress aren't affecting macroeconomic factors derived from the supply and demand of the currency of trade. More simply, you are conflating money as store-of-value and money as medium-of-exchange.