Money

Money is an IOU that agents can trade. It is a conditional claim of ownership of a stated quantity of a scarce thing. The issuer will give that thing at a future date, and agents can transfer the claim. The holder of the money holds the claim, and each trade moves the claim. Money is not a promise to give value, because a promise alone binds no agent. Money is ownership that moves from agent to agent, on the terms that the money sets.