A deadweight loss is the irrecoverable reduction in economic efficiency that occurs when a free-market equilibrium is disturbed by a market intervention or other shock to supply and/or demand. In economic theory, free markets are beneficial to society because they allow consumers and producers to exchange goods and services for money and both sides of the market gain at the equilibrium price in terms of consumer surplus and producer surplus. In a simple economy with just one

A demand curve shows the relationship between an item’s price and the quantity of the item demanded, either by an individual or by all participants in the market. Demand curves are downward-sloping for most items as greater quantities are demanded at lower prices.