So I was reading this comment on slashdot, when I realized what was missing from El Niquador's implementation of the Stone Society:
Originally my plan was to have each "contributing citizen" - an Officer in the Stone Society - recieve a quantity of stones at each terms elapsement. These would travel as for votes, and work similarly. Trade for goods would be set up using a similar, parallel, but distinct system (because I dislike the money = power equation that seems to arise in Stone Society naive implementations I can envision). The stones and the moneystones both decay which is to say their value lessens over time. To keep it simple, they have an expiry date. This keeps the economy moving, right? Sure. But what, as my mother pointed out last time I talked to her about it, about savings? What if you want to buy something big? The last thing I want is for a debt-system to appear in El Niquador. Debt is poison! Badness!
I think a good answer would be to make it so that moneystones can be preserved for some significant multiple of terms by spending other moneystones on their preservation. Suppose that a term is one month: given two moneystones, both of which would normally expire in a month, you can spend one to keep the other usable for a year. Very cool.
Of course, looking back on the Stone Society, it really does seem to work better. I did sort of forget about the whole "new things need new money" aspect of an economy. And the word I was thinking of was demurrage.