MARKET FAILURE: A condition in which a market does not efficiently allocate resources to achieve the greatest possible consumer satisfaction. The four main market failures are--(1) public good, (2) market control, (3) externality, and (4) imperfect information. In each case, a market acting without any government imposed direction, does not direct an efficient amount of our resources into the production, distribution, or consumption of the good. See also | market | fifth rule of imperfection | sixth rule of ignorance | public good | market control | externalities | production | consumption | information | pollution | regulation |