 Suppose that prices are set by planners. Hayek says with a thought more characteristic of neoclassical economists: “Only prices determined on the free market will bring it about that demand equals supply” (Hayek 1960, 63). Price controls—floors and ceilings—make buyers and sellers less able to respond to the signals they would send each other if they could raise their offer or lower their asking price. If price cannot rise, then buyers cannot signal producers that demand has increased and that producers would sell more if they were to increase supply. And if producers do not increase supply, rising demand results in shortages rather than economic growth. (See especially Zwolinski 2008 for further  elaboration.)[3]