The fact that economic problems stated in terms of one set of variables can also be considered in terms of an alternative set. For example, in linear programming, the problem may be to maximize the value of output subject to resource constraints. The dual problem corresponding to this involves choosing shadow prices to minimize the value put on resources, consistent with firms breaking even producing outputs subject to constraints imposed by the available techniques of production. It can be shown that these approaches lead to the same results. Which problem is simpler to handle computationally varies from case to case.

• accounting period
• accounts
• accounts, consolidated
• accounts payable
• accounts receivable
• accumulation, capital
• acid rain
• acquisition
• acquisition company
• ACT
• action
• actuarially fair odds
• actuary
• adaptive expectations
• adequacy, capital
• adjustable peg
• adjustment
• adjustment costs
• adjustment, price and quantity
• adjustment programme
• adjustment to factor cost
• administered price
• administration
• ad valorem tax
• Advance Corporation Tax