Economics the study of how society manages its scarce resources
Efficiency the property of society getting the most it can from its scarce resources
Equity the property of distributing economic prosperity fairly among the members of society
Opportunity cost whatever must be given up to obtain some item
Marginal changes small incremental adjustments to a plan of action
Market economy an economy that allocates resources through the decentralized decisions of many firms and households as they interact in markets for goods and services
Market failure a s/tuition in which a market left on its own fails to allocate resources efficiently
Externality the impact of one person’s actions on the well-being of a bystander
Market power the ability of a single economic actor (or small group of actors) to have a substantial influence on market prices
Productivity the quantity of goods and services produced from each hour of a worker’s time
Inflation an increase in the overall level of prices in the economy
Philips curve a curve that shows the short-run tradeoff between inflation and unemployment
Business cycle fluctuations in economic activity，such as employment and produaion
Circular-flow diagram a visual model of the economy that shows how dollars flow through markets among households and firms
Production possibilities frontier a graph that shows the combinations of output that the economy can possibly produce given the available factors of production and the available production technology
Positive statements claims that attempt to do describe the world as it is
Normative statements claims that attempt to prescribe how the world should be
Absolute advantage the comparison among producers of a good according to their productivity
Opportunity cost whatever must be given up to obtain some item
Comparative advantage the comparison among producers of a good according to their opportunity cost
Imports goods produced abroad and sold domestically
Exports goods produced domestically and sold abroad
Market a group of buyers and sellers of a particular good or service
Competitive market a market in which there are many buyers and many sellers so that each has a negligible impact on the market price
Quantity demanded the amount of a good that buyers are willing and able to-purchase
Law of demand the claim that, other things equal, the quantity demanded of a good falls when the price of the good rises
Demand schedule a table that shows the relationship between the price of a good and-the quantity demanded
Demand curve a graph of the relationship between the price of a good and the quantity demanded
Normal good a good for which, other things equal, an increase in income leads to an increase in demand
Inferior good a good for which, other things equal, an increase in income leads ‘to a decrease in demand
Substitutes two goods for which an increase in the price of one leads to an increase in the demand for the other
Complements two goods for which an increase in the price of one leads to a decrease in the demand for the other
Quantity supplied the amount of a good that sellers are willing and able to sell
Law of supply the claim that, other things equal, the quantity supplied of a good rises when the price of the good rises
Supply schedule a table that shows the relationship between the price of a good and the quantity supplied
Supply curve a graph of the relationship between the price of a good and the quantity supplied
Equilibrium a situation in which the price has reached the level where quantity supplied equals quantity demanded
Equilibrium price the price that balances quantity supplied and quantity demanded
Equilibrium quantity the quantity supplied and the quantity demanded at the equilibrium price
Surplus a situation in which quantity supplied is greater than quantity demanded
Shortage a situation in which quantity demanded is greater than quantity supplied
Laws of supply and demand the claim that the price of any good adjusts to bring the quantity supplied and the quantity demanded for that good into balance
Elasticity a measure of the responsiveness of quantity demanded or quantity supplied to one of its determinants
Price elasticity of demand a measure of how much the quantity demanded of a good responds to a change in the price of that good, computed as the e percentage change in quantity demanded divided by the percentage change in price
Income elasticity of demand a measure of how much the quantity demanded of a good responds to a change in consumers’ income, computed as the percentage change tn quantity demanded divided by the percentage change in income
Cross-price elasticity of demand a measure of how much the quantity demanded of one good respond to a change in the price of another good, computed as the percentage change m quantity demanded of the first good divided by the percentage change in the price of the second good
Price elasticity of supply a measure of how much the quantity supplied of a good responds to a change in the price of that good, computed as the percentage change in quantity supplied divided by the percentage change in price
Price ceiling a legal maximum on the price at which a good can be sold
Price floor a legal minimum on the price at which a good can be sold
Tax incidence the manner in which the burden of a tax is shared among participants in a market
Welfare economics the study of how the allocation of resources affects economic well-being
Willingness to pay the maximum amount that a buyer will pay for a good
Consumer surplus a buyer’s willingness to pay minus the amount the buyer actually pays
Cost the value of everything a seller must give up to produce a good
Producer surplus the amount a seller is paid for a good minus the seller’s cost
Efficiency the property of a resource allocation of maximizing the total surplus received by all members of society
Equity the fairness of the distribution of well-being among the members of society
Deadweight loss the fall in total surplus that results from a market distortion, such as a tax
World price the price of a good that prevails in the world market for that good
Tariff a tax on goods produced abroad and sold domestically
Import quota a limit on the quantity of a good that can be produced abroad and sold domestically
Externality the uncompensated impact of one person’s actions on the well-being of a bystander
Internalizing an externality altering incentives so that people take account of the external effects of their actions
Coase theorem the proposition that if private parties can bargain without cost over the allocation of resources, they can solve the problem of externalities on their own
Transaction costs the costs that parties incur in the process of agreeing and following through on a bargain
Pigovian tax a tax enacted to correct the effects of a negative externality
Excludability the property of a good whereby a person can be prevented from using it
Rivalry the property of a good whereby one person’s use diminishes other people’s use
Private goods goods that are both excludable and rival
Public goods goods that are neither excludable nor rival
Common resources goods that are rival but not excludable
Free rider a person who receives the benefit of a good but avoids paying for it
Cost-benefit analysis a study that compares the costs and benefits to society of providing a public good
Tragedy of the Commons a parable that illustrates why common resources get used more than is desirable from the standpoint of society as a whole
Budget surplus an excess of government receipts over government spending
Budget deficit an excess of government spending over government receipts
Average tax rate total taxes paid divided by total income
Marginal tax rate the extra taxes paid on an additional dollar of income
Lump-sum tax a tax that is the same amount for every person
Benefits principle the idea that people should pay taxes based on the benefits they receive from government services
Ability-to-pay principle the idea that taxes’ should be levied on a person according to how well that person can shoulder the burden
Vertical equity the idea that taxpayers with a greater ability to pay taxes should pay larger amounts
Horizontal equity the idea that taxpayers with similar abilities to pay taxes should pay the same amount
Proportional tax a tax for which high-income and low-income taxpayers pay the same fraction of income
Regressive tax a tax for which high-income taxpayers pay a smaller fraction of their income than do low-income taxpayers
Progressive tax a tax for which high-income taxpayers pay a larger fraction of their income than do low-income taxpayers
Total revenue the amount a firm receives for the sale of its output
Total cost the market value of the inputs a firm uses in production
Profit total revenue minus total cost
Explicit costs input costs that require an outlay of money by the firm
Implicit costs input costs that do not require an outlay of money by the firm
Economic profit total revenue minus total cost, including both explicit and implicit costs
Accounting profit total revenue minus total explicit cost
Production function the relationship between quantity of inputs used to make a good and the quantity of output of the good
Marginal product the increase in output that arises from an additional unit of input
Diminishing marginal product the property whereby the marginal product of an input declines as the quantity of the input increases
Fixed costs costs that do not vary with the quantity of output produced
Variable costs costs that do vary with the quantity of output produced
Average total cost total cost divided by the quantity of output
Average fixed cost fixed costs divided by the quantity of output
Average variable cost variable costs divided by the quantity of output
Marginal cost the increase in total cost that arises from an extra unit of production
Efficient scale the quantity of output that minimizes average total cost
Economies of scale the property whereby long-run average total cost falls as the quantity of output increases
Diseconomies of scale the property whereby long-run average total cost rises as the quantity of output increases
Constant returns to scale the property whereby long-run average total cost stays the same as the quantity of output changes
Competitive market a market with many buyers and sellers trading identical products so that each buyer and setter is a price taker
Average revenue total revenue divided by the quantity sold
Marginal revenue the change in total revenue from an additional unit sold
Sunk cost a cost that has already been committed and cannot be recovered
Monopoly a firm that is the sole seller of a product without close substitutes
Natural monopoly a monopoly that arises because a single firm can supply a good or service to an entire market at a smaller cost than could two or more firms
Price discrimination the business practice of selling the same good at different prices to different customers
Oligopoly a market structure in which only a few settlers offer similar or identical products
Monopolistic competition a market structure in which many firms sell products that are similar but not identical
Collusion an agreement among firms in a market about quantities to produce or prices to charge
Cartel a group of firms acting in unison
Nash equilibrium a situation in which economic actors interacting with one another each choose their best strategy given the strategies that a/l the other actors have chosen
Game theory the study of how people behave in strategic situations
Prisoners’ dilemma a particular “game’ between two captured prisoners that illustrates why cooperation is difficult to maintain even when it is mutually beneficial
Dominant strategy a strategy that is best for a player in a game regardless of the strategies chosen by the other players
Monopolistic competition a market structure in which many firms sell products that are similar but not identical
Factors of production the inputs used’ to produce goods and services
Production function the relationship between the quantity of inputs used to make a good and the quantity of output of that good
Marginal product of labor the increase in the amount of output from an additional unit of labor
Diminishing marginal product the property whereby the marginal product of an input declines as the quantity of the input increases
Value of the marginal product the marginal product of an input times the price of the output
Capital the equipment and structures used to produce goods and services
Compensating differential a difference in wages that arises to offset the nonmonetary characteristics of different jobs
Human capital the accumulation of investments in people, such as education and on-the-job training
Union a worker association that bargains with employers over wages and working conditions
Strike the organized withdrawal of labor from a firm by union
Efficiency wages above-equilibrium wages paid by firms in order to increase worker productivity
Discrimination the offering of different opportunities to similar individuals who differ only by race, ethnic group, sex, age, or other personal characteristics
Poverty rate the percentage of the population whose family income falls below an absolute level called the poverty line
Poverty line an absolute level of income set by the federal government for each family size below which a family is deemed to be in poverty
In-kind transfers transfers to the poor given in the form of goods and services-rather than cash
Life cycle the regular pattern of income variation over a person’s life
Permanent income a person’s normal income
Utilitarianism the political philosophy according to which the government should choose policies to maximize the total utility of everyone in society
Utility a measure of happiness or satisfaction
Liberalism the political philosophy according to which the government should choose policies deemed to be just, as evaluated by an impartial observer behind a “veil of ignorance’’
Maximin criterion the claim that the government should aim to maximize the well-being of the worst-off person in society
Libertarianism the political philosophy according to which the government should punish crimes and enforce voluntary agreements but not redistribute income
Welfare government programs that supplement the incomes of the needy
Negative income tax a tax system that collects revenue from high-income households and gives transfers to tow-income households
Budget constraint the limit on the consumption bundles that a consumer can afford
Indifference curve a curve that shows consumption bundles that give the consumer the same level of satisfaction
Marginal rate of substitution the rate at which a consumer is willing to trade one good for another
Perfect substitutes two goods with straight-line indifference curves
Perfect complements two goods with right-angle indifference curves
Normal good a good for which an increase in income raises the quantity demanded
Inferior good a good for which an increase in income reduces the quantity demanded
Income effect the change in consumption that results when a price change moves the consumer to a higher or lower indifference curve
Substitution effect the change in consumption that results when a price change moves indifference curve to a point with new marginal rate of substitution
Giffen good a good tor which an increase in the price raises the quantity demanded
Moral hazard the tendency of a person who is imperfectly monitored to engage in dishonest or otherwise undesirable behavior
Agent a person who is performing an act for another person, called the principal
Principal a person for whom another person, called the agent, is performing some act
Adverse selection the tendency for the mix of unobserved attributes to become undesirable from the standpoint of an uninformed party
Signaling an action taken by an informed party to reveal private information to an uninformed party
Screening an action taken by an uninformed party to induce an informed party to reveal information
Condorcet paradox the failure of majority rule to produce transitive preferences for society
Arrow’s impossibility theorem a mathematical result showing that, under certain assumed conditions, there is no scheme for aggregating individual preferences into a valid set of social preferences
Ability-to-Pay principle (税收的)能力支付原则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
Accounting profit会计利润 total revenue minus total explicit cost
Adverse selection逆向选择the tendency for the mix of unobserved attributes to become undesirable from the standpoint of an uninformed party
Agent代理人 a person who is performing an act for another person, called the principal
Arrow ’s impossibility theorem阿罗不可能定理 a mathematical result showing that, under certain assumed conditions, there is no scheme for aggregating individual preferences into a valid set of social preferences
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 variable costs divided by the quantity of output
Benefits principle受益原则 the idea that people should pay taxes based on the benefits they receive from government services
Budget constraint预算约束 the limit on the consumption bundles that a consumer can afford
Budget deficit预算赤字 an excess of government spending over government receipts
Budget surplus预算盈余 an excess of government receipts over government spending
Business cycle经济周期 fluctuations in economic activity, such as employment and production
Capital资产 the equipment and structures used to produce goods and services
Cartel卡特尔a group of firms acting in unison
Circular-flow diagram循环流向图 a visual model of the economy that shows how dollars flow through markets among households and firms
Coase theorem科斯定理 the proposition that if private parties can bargain without cost over the allocation of resources, they can solve the problem of externalities on their own
Collusion共谋 an agreement among firms in a market about quantities to produce or prices to charge
Common resources共源 goods that are rival but not excludable
Comparative advantage比较优势 the comparison among producers of a good according to their opportunity cost
Compensating differential补偿性工资差别 a difference in wages that arises to offset the nonmonetary characteristics of different jobs
Competitive market竞争性市场 a market with many buyers and sellers trading identical products so that each buyer and seller is a price taker
Complements互补性商品 two goods for which an increase in the price of one leads to a decrease in the demand for the other
Condorcet paradox孔多塞悖论（投票悖论） the failure of majority rule to produce transitive preferences for society
Constant returns to scale规模报酬不变 the property whereby long-run average total cost stays the same as the quantity of output changes
Consumer surplus消费者剩余 a buyer’s willingness to pay minus the amount the buyer actually pays
Cost成本 the value of everything a seller must give up to produce a good
Cost-benefit analysis成本收益分析 a study that compares the costs and benefits to society of providing a public good
Cross-price elasticity of demand需求的交叉价格弹性 a measure of how much the quantity demanded of one good responds to a change in the price of another good, computed as the percentage change in quantity demanded of the first good divided by the percentage change in the price of the second good
Deadweight loss无谓损失 the fall in total surplus that results from a market distortion, such as a tax
Demand curve需求曲线 a graph of the relationship between the price of a good and the quantity demanded
Demand schedule需求表 a table that shows the relationship between the price of a good and the quantity demanded
Diminishing marginal product边际产品递减 the property whereby the marginal product of an input declines．As the quantity of the input increases
Discrimination歧视 the offering of different opportunities to similar individuals who differ only by race, ethnic group, sex, age, or other personal characteristics
Diseconomies of scale规模不经济 the property whereby long-run average total cost rises as the quantity of output increases
Dominant strategy占优策略 a strategy that is best for a player in a game regardless of the strategies chosen by the other players
Economic profit经济利润 total revenue minus total cost, including both explicit and implicit costs
Economics经济学 the study of how society manages its scarce resources
Economies of scale规模经济 the property whereby long-run average total cost falls as the quantity of output increases
Efficiency效率 the property of society getting the most it can from its scarce resources
Efficiency wages效率工资 above-equilibrium wages paid by firms in order to increase worker productivity
Efficient scale有效规模 the quantity of output that minimizes average total cost
Elasticity弹性 a measure of the responsiveness of quantity demanded or quantity supplied to one of its determinants
Equilibrium均衡 a situation in which the price has reached the level where quantity supplied equals quantity demanded
Equilibrium price均衡价格 the price that balances quantity supplied and quantity demanded
Equilibrium quantity均衡数量 the quantity supplied and the quantity demanded at the equilibrium price
Equity平等 the property of distributing economic prosperity fairly among the members of society
Excludability排他性 the property of a good whereby a person can be prevented from using it
Explicit costs显性成本 input costs that require an outlay of money by the firm
Exports出口 goods produced domestically and sold abroad
Externality外部性 the uncompensated impact of one person’s actions on the wellbeing of a bystander
Factors of production生产要素 the inputs used to produce goods and services
Fixed casts固定成本 costs that do not vary with the quantity of output produced
Free rider免费搭车者 a person who receives the benefit of a good but avoids paying for it
Game theory博弈论 the study of how people behave in strategic situations
Giffen good吉芬商品 a good for which an increase in the price raises the quantity demanded
Horizontal equity横向公平 the idea that taxpayers with similar abilities to pay taxes should pay the same amount
Human capital人力资本 the accumulation of investments in people, such as education and on-the-job training
Implicit costs隐性成本 input costs that do not require an outlay of money by the firm
Import quota进口配额 a limit on the quantity of a good that can be produced abroad and sold domestically
Imports进口 goods produced abroad and sold domestically
Income effect收入效应 the change in consumption that results when a price change moves the consumer to a higher or lower indifference curve
Income elasticity of demand需求的收入弹性 a measure of how much the quantity demanded of a good responds to a change in consumers’ income, computed as the percentage change in quantity demanded divided by the percentage change in income
Indifference curve无差异曲线 a curve that shows consumption bundles that give the consumer the same level of satisfaction
Inferior good低档物品 a good for which, other things equal, an increase in income leads to a decrease in demand
Inflation通货膨胀 an increase in the overall level of prices in the economy
In-kind transfers实物转移支付 transfers to the poor given in the form of goods and services rather than cash
Internalizing an externality外部性的内在化 altering incentives so that people take account of the external effects of their actions
Law of demand需求定理 the claim that, other things equal, the quantity demanded of a good falls when the price of the good rises
Law of supply and demand需求与供给定理 the claim that the price of any good adjusts to bring the quantity supplied and the quantity demanded for that good into balance
Liberalism自由主义 the political philosophy according to which the government should choose policies deemed to be just, as evaluated by an impartial observer behind a “veil of ignorance”
Libertarianism自由至上主义 the political philosophy according to which the government should punish crimes and enforce voluntary agreements but not redistribute income
Life cycle生命周期 the regular pattern of income variation over a person’s life
Lump-sum tax定额税 a tax that is the same amount for every person
Macroeconomics宏观经济学 the study of economy-wide phenomena, including inflation, unemployment, and economic growth
Marginal changes边际变动 small incremental adjustments to a plan of action
Marginal cost边际成本 the increase in total cost that arises from an extra unit of production
Marginal product边际产品 the increase in output that arises from an additional unit of input
Marginal product of labor劳动的边际产品 the increase in the amount of output from an additional unit of labor
Marginal rate of substitution边际替代率 the rate at which a consumer is willing to trade one good for another
Marginal revenue边际收益 the change in total revenue from an additional unit sold
Marginal tax rate边际税率 the extra taxes paid on an additional dollar of income
Market市场 a group of buyers and sellers of a particular good or service
Market economy市场经济 an economy that allocates resources through the decentralized decisions of many firms and households as they interact in markets for goods and services
Market failure市场失灵 a situation in which a market left on its own fails to allocate resources efficiently
Market power市场势力 the ability of a single economic actor (or small group of actors) to have a substantial influence on market prices
Maximin criterion极大极小准则 the claim that the government should aim to maximize the well-being of the worst-off person in society
Median voter theorem中位选举人定理 a mathematical result showing that if voters are choosing a point along a line and each voter wants the point closest to his most preferred point, then majority rule will pick the most preferred point of the median voter
Microeconomics微观经济学 the study of how households and firms make decisions and how they interact in markets
Monopolistic competition垄断竞争 a market structure in which many firms sell products that are similar but not identical
Monopoly垄断 a firm that is the sole seller of a product without close substitutes
Moral hazard道德风险 the tendency of a person who is imperfectly monitored to engage in dishonest or otherwise undesirable behavior
Nash equilibrium纳什均衡 a situation in which economic actors interacting with one another each choose their best strategy given the strategies that all the other actors have chosen
Natural monopoly自然垄断 a monopoly that arises because a single firm can supply a good or service to an entire market at a smaller cost than could two or more firms
Negative income tax负所得税 a tax system that collects revenue from high-income households and gives transfers to low-income households
Normal good正常商品 a good for which, other things equal, an increase in income leads to an increase in demand
Normative statements规范性表述 claims that attempt to prescribe how the world should be
Oligopoly寡头 a market structure in which only a few sellers offer similar or identical products
Opportunity cost机会成本 whatever must be given up to obtain some item
Perfect complements完全互补品 two goods with right-angle indifference curves
Perfect substitutes完全替代品two goods with straight-line indifference curves
Permanent income持久性收入 a person’s normal income
Phillips curve菲利普斯曲线 a curve that shows the short-run tradeoff between inflation and unemployment
Pigovian tax庇古税 a tax enacted to correct the effects of a negative externality
Positive statements实证表述 claims that attempt to describe the world as it is
Poverty line贫困线 an absolute level of income set by the federal government for each family size below which a family is deemed to be in poverty
Poverty rate贫困率 the percentage of the population whose family income falls below an absolute level called the ‘poverty line
Price ceiling价格天花板（上限） a legal maximum on the price at which a good can be sold
Price discrimination价格歧视 the business practice of selling the same good at different prices to different customers
Price elasticity of demand需求的价格弹性 a measure of how much the quantity demanded of a good responds to a change in the price of that good, computed as the percentage change in quantity demanded divided by the percentage change in price
Price elasticity supply供给的价格弹性 a measure of how much the quantity supplied of a good responds to a change in the price of that good, computed as the percentage change in quantity supplied divided by the percentage change in price
Price floor价格地板I下限） a legal minimum on the price at which a good can be sold
Principal委托人 a person for whom another person, called the agent, is performing some act
Prisoners’ dilemma囚徒困境 a particular “game” between two captured prisoners that illustrates why cooperation is difficult to maintain even when it is mutually beneficial
Private goods私人物品 goods that are both excludable and rival
Producer surplus生产者剩余 the amount a seller is paid for a good minus the seller’s cost
Production function生产函数 the relationship between quantity of inputs used to make a good and the quantity of output of that good
Production possibilities frontier生产可能性曲线 a graph that shows the combinations of output that the economy can possibly produce given the available factors of production and the available production technology
Productivity生产率 the quantity of goods and services produced from each hour of a worker’s time
Profit利润 total revenue minus total cost
Progressive tax累进税 a tax for which high-income taxpayers pay a larger fraction of their income than do low-income taxpayers
Proportional tax比例税 a tax for which high-income and low-income taxpayers pay the same fraction of income
Public goods公品 goods that are neither excludable nor rival
Quantity demanded需求数量 the amount of a good that buyers are willing and able to purchase
Quantity supplied供给数量 the amount of a good that sellers are willing and able to sell
Regressive tax累退税 a tax for which high-income taxpayers pay a smaller fraction of their income than do low-income taxpayers
Rivalry竞争 the property of a good whereby one person’s use diminishes other people’s use
Scarcity稀缺性 the limited nature of society’s resources
Screening筛选 an action taken by an uninformed party to induce an informed party to reveal information
Shortage短缺 a situation in which quantity demanded is greater than quantity supplied
Signaling信号显示 an action taken by an informed party to reveal private information to an uninformed party
Strike罢工 the organized withdrawal of labor from a firm by a union
Substitutes替代品 two goods for which an increase in the price of one leads to an increase in the demand for the other
Substitution effect替代效应 the change in consumption that results when a price change moves the consumer along a given indifference curve to a point with a new marginal rate of substitution
Sunk cost沉淀成本 a cost that has already been committed and cannot be recovered
Supply curve供给曲线 a graph of the relationship between the price of a good and the quantity supplied
Supply schedule供给表 a table that shows the relationship between the price of a good and the quantity supplied
Surplus过剩 a situation in which quantity supplied is greater than quantity demanded
Tariff关税 a tax on goods produced abroad and sold domestically
Tax incidence税收归宿 the manner in which the burden of a tax is shared among participants in a market
Total cost总成本 the market value of the inputs a firm uses in production
Total revenue (for a firm)总收益 the amount a firm receives for the sale of its output
Total revenue (in a market)总收益 the amount paid by buyers and received by sellers of a good, computed as the price of the good times the quantity sold
Tragedy of the Commons公共地的悲剧 a parable that illustrates why common resources get used more than is desirable from the standpoint of society as a whole
Transaction costs交易成本 the costs that parties incur in the process of agreeing and following through on a bargain
Union工会 a worker association that bargains with employers over wages and working conditions
Utilitarianism功利主义 the political philosophy according to which the government should choose policies to maximize the total utility of everyone in society
Utility效用 a measure of happiness or satisfaction
Value of the marginal product边际产品价值 the marginal product of an input times the price of the output
Variable costs可变成本 costs that vary with the quantity of output produced
Vertical equity纵向公平 the idea that taxpayers with a greater ability to pay taxes should pay larger amounts
Welfare福利 government programs that supplement the incomes of the needy
Welfare economics福利经济学 the study of how the allocation of resources affects economic well-being
Willingness to pay支付意愿 the maximum amount that a buyer will pay for a good
World price世界价格 the price of a good that prevails in the world market for that good下载本文
