A price ceiling is a government-imposed price control or limit on how high a price is charged for a product. Governments intend price ceilings to protect consumers from conditions that could make necessary commodities unattainable[citation needed]. However, a price ceiling can cause problems if imposed for a long period without controlled rationing. Price ceilings can produce negative results when the correct solution would have been to increase supply[citation needed]. Misuse occurs when a government misdiagnoses a price as too high when the real problem is that the supply is too low[citation needed]. In an unregulated market economy price ceilings do not exist.