In post Keynesian models, the supply of it is a function of the demand for bank credit.
Narayana Kocherlakota suggested that this concept and memory are equivalent, by showing equivalent economic allocations for a given economy when this is swapped with perfect memory. Miguel Sidrauski did pioneering work to introduce this concept to utility functions. In post Keynesian models, the supply of it is a function of the demand for bank credit. Changes in its supply have no impact on real variables according to the "neutrality" theory for it, and have a direct impact on the price level according to the "quantity" theory of this concept. For 10 points, identify this economic concept, whose supply is measured by M1and M2, and which was once backed by a gold standard in many countries.
Narayana Kocherlakota suggested that this concept and memory are equivalent, by showing equivalent economic allocations for a given economy when this is swapped with perfect memory.
money [accept money supply until "supply" from people who are not listening]