Term	Definition
Price ceiling	A legally determined maximum price that sellers may charge.
Price floor	A legally determined minimum price that sellers may receive.
Marginal benefit	The additional benefit to a consumer from consuming one more unit of a good or service.
Consumer surplus	The difference between the highest price a consumer is willing to pay and the price the consumer actually pays.
Marginal cost	The additional cost to a firm of producing one more unit of a good or service.
Producer surplus	The difference between the lowest price a firm would have been willing to accept and the price it actually receives.
Economic surplus	The sum of consumer surplus and producer surplus.
Deadweight loss	The reduction in ecoomic surplus resulting from a market not being in competitive equilibrium.
Economic efficiency	A market outcome i which the marginal benefit to consumers of the last unit produced is equal to its marginal cost of production, and in which the sum of consumer surplus an producer surplus is at a maximum.
Black market	Buying and selling at prices that violate government price regulations.
Tax incidence	The actual division of the burden of a tax between buyers and sellers in a market.