Discrimination is often the basis for government price controls. All rationing mechanisms involve some form of discrimination. Price ceilings are legislatively imposed maximum prices. Set below equilibrium price to be effective. Artificially low price leads to persistent shortage.
Low price increases quantity demanded.
Low price reduces quantity supplied. Persistent shortage requires an alternative rationing mechanism since the price is not allowed to ration the commodity. Alternative rationing mechanisms. Queuing Time spent in line imposes an opportunity cost on buyers. The nonpecuniary price is the opportunity cost of acquiring the item through line standing.