세금

An excise tax is a mandatory financial charge levied on the sale of specific goods, such as cigarettes or sugary drinks. Governments impose excise taxes to generate revenue and discourage consumption of certain products. Unlike general sales taxes, excise taxes target particular items deemed harmful or subject to policy control, making them a tool for both fiscal and behavioral objectives.

When an excise tax is imposed, the supply curve shifts upward by the tax amount, reflecting higher production costs for sellers. This shift results in a new equilibrium where the price consumers pay increases while the quantity sold decreases. The higher price and reduced availability move the market away from its original equilibrium point.

Both consumer and producer surplus decline when an excise tax is imposed. Consumers pay higher prices and buy less, reducing their surplus. Producers sell fewer units and keep less revenue after paying the tax, shrinking their surplus. This reduction in both surpluses reflects the decline in economic welfare for market participants.

Government tax revenue is calculated by multiplying the tax amount per unit by the quantity of goods sold at the new equilibrium. For example, if a tax of $2 per unit is imposed and 100 units are sold, the government collects $200 in revenue. This revenue represents the transfer of value from consumers and producers to the government.

Deadweight loss represents the value of transactions that would have occurred in a tax-free market but no longer happen due to the higher price and reduced quantity. On a supply-demand graph, it appears as a triangular area between the curves. This loss reflects mutually beneficial trades that are eliminated, reducing overall market efficiency and economic welfare.

Although taxes generate revenue for the government, they reduce overall economic welfare by shrinking consumer and producer surplus and creating deadweight loss. The value transferred to government revenue is less than the combined loss in consumer and producer surplus. This net loss means the market becomes less efficient, as some mutually beneficial exchanges no longer take place.

An excise tax transfers benefits from consumers and producers to the government. Consumers lose surplus by paying higher prices, producers lose surplus by selling fewer units at lower net prices, and the government gains tax revenue. This redistribution reduces the total economic benefits created by the market, as deadweight loss represents value that benefits no one.