The excess of the total harm done by a tax over the actual revenue raised. An indirect tax raises the price of the taxed good to the consumer. The quantity sold falls, as consumers only buy units of the good for which their benefits exceed the tax-inclusive price. There are thus some units where the benefit to the consumer would be higher than the cost of production, but lower than the tax-inclusive price. The consumer surplus which could have been made on these units is lost; this is the ‘triangle of loss’. Similarly, direct taxes are liable to reduce effort, since workers will only exert effort whose cost to them is less than net-of-tax pay. They will not work where the cost to them is less than the pre-tax wage but more than the post-tax wage; the producer's surplus which could have been made on these units is lost. Most taxes produce some deadweight burden: a well-designed tax system seeks to minimize the deadweight burden involved in raising any given total tax revenue.

• ad valorem tax
• Advance Corporation Tax
• advances
• advantage
• adverse selection
• adverse supply shock
• advertising
• Advisory, Conciliation and Arbitration Service
• AFDC
• AFL-CIO
• after-sales service
• after-tax income
• age-earnings profile
• agency
• agent
• agglomeration economies
• aggregate demand
• aggregate demand schedule
• aggregate supply
• aggregation
• AGM
• agreement
• agricultural protection
• aid
• Aid to Families with dependent Children