Ability-to-pay principle 能力纳税原则

　　The idea that taxes should be levied on a person according to how well that person can shoulder the burden

　　Absolute advantage 绝对优势

　　The comparison among producers of a good according to their productivity

　　Aggregate-demand curve 总需求曲线

　　A curve that shows the quantity of goods and services that households, firms, and the government want to buy at any price level

　　Aggregate-supply curve 总供给曲线

　　A curve that shows the quantity of goods and services that firms choose to produce and sell at any level

　　Appreciation 升值

　　An increase in the value of a currency as measured by the amount of foreign currency it can buy

　　Automatic stabilizers 自动稳定器

　　Changes in fiscal policy that stimulate aggregate demand when the economy goes into a recession without policymakers having to take any deliberate action

　　Average fixed cost 平均固定成本

　　Fixed costs divided by the quantity of output

　　Average revenue 平均收益

　　Total revenue divided by the quantity sold

　　Average tax rate 平均税率

　　Total taxes paid divided by total income

　　Average total cost 平均总成本

　　Total cost divided by the quantity of output

　　Average variable cost 平均可变成本

　　Variables costs divided by the quantity of output

　　Accelerator 加速数

　　the effect on GDP of the increase in investment that results from an increase in output. For instance, the greater output leads a firm to believe that the demand for its products will rise in the future; the resulting increase in investment leads to growth in output and still further increases in investment, accelerating the expansion of the economy

　　Acquired endowments 后天禀赋

　　resources a country builds for itself, like a network of roads or an educated population，examda.

　　Adaptive expectations 适应性预期

　　expectations based on the extrapolation of events in the recent past into the future

　　aggregate expenditures schedule 总支出曲线

　　a curve that traces out the relationship between expenditures--the sum of consumption, investment, government expenditures, and net exports--and the national income, at a fixed price level

　　antitrust laws 反托拉斯法

　　laws that discourage monopoly and restrictive practices and encourage greater competition

　　arbitrage 套利

　　the process by which assets with comparable risk, liquidity, and tax treatment are priced to yield comparable expected returns，examda.

　　adverse selection 逆向选择

　　principle that says that those who most want to buy insurance tend to be those most at risk, but charging a high price for insurance (to cover the high risk)will discourage those at less risk from buying insurance at all

　　asset 资产

　　any item that is long-lived, purchased for the service it renders over its life and for what one will receive when one sells it

　　assistance in kind 实物援助

　　public assistance that provides particular goods and services, like food or medical care, rather than cash，examda.

　　asymmetric information 信息不对称

　　a situation in which the parties to a transaction have different information, as when the seller or a used car has more information about its quality then the buyer

　　autonomous consumption 自主消费

　　that part of consumption that does not depend on income，examda.

　　average costs 平均成本

　　the total costs divided by the total output

　　average productivity 平均产量

　　total quantity divided by the total quantity of input