Deadweight loss

A deadweight loss, also known as excess burden or allocative inefficiency, is a loss of economic efficiency that can occur when the free market equilibrium for a good or a service is not achieved. That can be caused by monopoly pricing in the case of artificial scarcity, an externality, a tax or subsidy, or a binding price ceiling or price floor such as a minimum wage. A deadweight loss, also known as excess burden or allocative inefficiency, is a loss of economic efficiency that can occur when the free market equilibrium for a good or a service is not achieved. That can be caused by monopoly pricing in the case of artificial scarcity, an externality, a tax or subsidy, or a binding price ceiling or price floor such as a minimum wage. Assume a market for nails where the cost of each nail is $0.10. Demand decreases linearly; there is a high demand for free nails and zero demand for nails at a price per nail of $1.10 or higher. The price of $0.10 per nail represents the point of economic equilibrium in a competitive market. If market conditions are perfect competition, producers would charge a price of $0.10, and every customer whose marginal benefit exceeds $0.10 would buy a nail. A monopoly producer of this product would typically charge whatever price will yield the greatest profit for themselves, regardless of lost efficiency for the economy as a whole. In this example, the monopoly producer charges $0.60 per nail, thus excluding every customer from the market with a marginal benefit less than $0.60. The deadweight loss due to monopoly pricing would then be the economic benefit foregone by customer with a marginal benefit of between $0.10 and $0.60 per nail. The monopolist has 'priced them out of the market', even though their benefit exceeds the 'true' cost per nail. Conversely, deadweight loss can also arise from consumers buying more of a product than they otherwise would based on their marginal benefit and the cost of production. For example, if in the same nail market the government provided a $0.03 subsidy for every nail produced, the subsidy would reduce the market price of each nail to $0.07, even though production actually still costs $0.10 per nail. Consumers with a marginal benefit of between $0.07 and $0.10 per nail would then buy nails, even though their benefit is less than the real production cost of $0.10. The difference between the cost of production and the purchase price then creates the 'deadweight loss' to society. A tax has the opposite effect of a subsidy. Whereas a subsidy entices consumers to buy a product that would otherwise be too expensive for them in light of their marginal benefit (price is lowered to artificially increase demand), a tax disuades consumers from a purchase (price is increased to artificially lower demand). This excess burden of taxation represents the lost utility for the consumer. A common example of this is the so-called sin tax, a tax levied against goods deemed harmful to society and individuals. For example, 'sin taxes' levied against alcohol and tobacco are intended to artificially lower demand for these goods; some would-be users are priced out of the market, i.e. total smoking and drinking are reduced. Harberger's triangle, generally attributed to Arnold Harberger, shows the deadweight loss (as measured on a supply and demand graph) associated with government intervention in a perfect market. Mechanisms for this intervention include price floors, caps, taxes, tariffs, or quotas. It also refers to the deadweight loss created by a government's failure to intervene in a market with externalities. In the case of a government tax, the amount of the tax drives a wedge between what consumers pay and what producers receive, and the area of this wedge shape is equivalent to the deadweight loss caused by the tax.