Price controls
Legal ceilings or floors on prices—rent caps, gasoline ceilings, wartime rationing—intended to shield consumers but often creating shortages or black markets.
When a ceiling holds prices below market-clearing levels, quantity demanded can exceed supply, inviting queues, favoritism, or informal payments. Controls also complicate inflation measurement because observed prices no longer freely equilibrate.
Policy history
Debates in the second half of the twentieth century pitted market pricing against administrative limits on increases. The topic surfaces whenever energy or housing spikes dominate politics.