The practical and theoretical meaning of the rise and fall of new local and virtual currencies suggest that two basic theories of money both have their validity and reasons for coexistence. The drive for increasing eﬀiciency in the payment mechanisms is in full swing and still presents many opportunities for improvement.
Shubik, Martin, "Simecs, Ithaca Hours, Berkshares, Bitcoins and Walmarts" (2014). Cowles Foundation Discussion Papers. 2348.