A price ceiling is a government- or group-imposed price control, or limit, on how high a price is charged for a product, commodity, or service. Governments use price ceilings ostensibly to protect consumers from conditions that could make commodities prohibitively expensive. Such conditions can occur during periods of high inflation, in the event of an investment bubble, or in the event of monopoly ownership of a product, all of which can cause problems if imposed for a long period without controlled rationing, leading to shortages. Further problems can occur if a government sets unrealistic price ceilings, causing business failures, stock crashes, or even economic crises. In unregulated market economies, price ceilings do not exist. While price ceilings are often imposed by governments, there are also price ceilings that are implemented by non-governmental organizations such as companies, such as the practice of resale price maintenance. With resale price maintenance, a manufacturer and its distributors agree that the distributors will sell the manufacturer's product at certain prices (resale price maintenance), at or below a price ceiling (maximum resale price maintenance) or at or above a price floor. Examples Rent control in New York City Rent control is a system where the government sets a price ceiling on rent (often in combination with eviction limitations and maintenance requirements). When soldiers returned from World War II and started families, which increased demand for apartments, but stopped receiving military pay, many of them could not deal with higher rents. The government put in price controls so that soldiers and their families could pay their rents and keep their homes. However, it increased the quantity demand for apartments and lowered the quantity supplied, and so the number of available apartments rapidly decreased until none were available for latecomers. Price ceilings create shortages when producers are allowed to abdicate market share or go unsubsidized. Apartment price control in Finland According to professors Niko Määttänen and Ari Hyytinen, price ceilings on Helsinki City Hitas apartments are highly inefficient economically. They cause queuing and discriminate against the handicapped, single parents, elderly, and others who are not able to queue for days. They cause inefficient allocation, as apartments are not bought by those willing to pay the most for them. Also, those who get an apartment are unwilling to leave it, even when their family or work situation changes, as they may not sell it at what they feel the