AP经济学的重点和难点知识(北京王府学校 傅莹)
高三经济学重难点考点讲解详细要点
高三经济学重难点考点讲解详细要点经济学是一门研究资源分配、生产、消费、投资、价格、市场等经济现象的科学。
对于高三学生来说，掌握经济学的基本概念、原理和方法，了解重难点考点，是取得好成绩的关键。
下面，我将对高三经济学重难点考点进行详细讲解。
1. 微观经济学部分1.1 市场需求与供给•需求曲线：需求曲线表示在不同的价格水平下，消费者愿意购买的商品数量。
需求曲线向下倾斜，表明价格与需求量呈负相关。
•供给曲线：供给曲线表示在不同的价格水平下，生产者愿意提供的商品数量。
供给曲线向上倾斜，表明价格与供给量呈正相关。
•市场均衡：市场均衡是指在某一价格水平下，市场需求量与供给量相等。
此时，商品的市场价格达到平衡，消费者与生产者均满意。
1.2 消费者行为与生产者行为•边际效用递减规律：随着消费量的增加，每增加一单位商品所带来的满足感逐渐减少。
•生产要素：生产要素包括劳动、土地、资本和企业家精神。
生产者通过合理配置这些要素，实现生产目标。
•生产可能性边界：生产可能性边界表示在资源有限的情况下，生产两种商品的最大可能组合。
1.3 价格与竞争策略•价格歧视：价格歧视是指企业根据消费者的需求和支付意愿，对同一商品实行不同价格的策略。
•市场竞争：市场竞争包括完全竞争、垄断竞争、寡头垄断和完全垄断。
不同市场竞争格局下，企业的定价策略和市场行为有所不同。
1.4 市场失灵与政府干预•市场失灵：市场失灵是指市场机制在资源配置方面存在不足，导致资源配置效率低下。
•政府干预：政府干预包括价格干预、产业政策、反垄断政策等，旨在纠正市场失灵，提高资源配置效率。
2. 宏观经济学部分2.1 国民经济总量与增长•国内生产总值（GDP）：GDP表示一个国家在一定时期内生产的所有最终商品和服务的市场价值总和。
•经济增长：经济增长是指国家或地区在一定时期内GDP、人均收入、就业等宏观经济指标的持续提高。
•经济周期：经济周期是指国民经济总量、就业、价格等宏观经济指标在一定时期内呈波动性变化的现象。
ap微观经济学知识点梳理
ap微观经济学知识点梳理AP微观经济学知识点梳理导语：AP微观经济学是一门重要的学科，它研究个体经济行为和市场经济运行规律。
掌握这门学科的知识点，有助于我们更好地理解和解读市场现象，并为未来的学业和职业做好准备。
本文将深入梳理AP微观经济学涵盖的主要知识点，概念和原理，并分享我对这些知识点的理解和观点。
第一部分：供给和需求1. 市场供给和需求的概念- 供给：指生产者为不同价格和数量的商品或服务所愿意提供的数量。
- 需求：指消费者愿意以不同价格购买的商品或服务的数量。
2. 需求和供给曲线- 需求曲线：表达不同价格下消费者所需求的商品或服务的数量。
- 供给曲线：表达不同价格下生产者愿意提供的商品或服务的数量。
3. 市场均衡- 基于供给和需求曲线的交点确定的价格和数量。
- 市场短期均衡和长期均衡的区别。
4. 价格弹性- 需求价格弹性和供给价格弹性的概念。
- 弹性的高低对市场变化的反应程度的影响。
第二部分：消费者行为1. 边际效用- 边际效用的定义和概念。
- 边际效用递减原理。
2. 选择和效用最大化- 理性消费者在多种选择下如何决策以实现效用最大化。
- 预算约束对消费者选择的影响。
3. 边际成本和边际效益- 边际成本和边际效益的概念。
- 边际成本和边际效益相等时的最优决策。
第三部分：生产者行为1. 生产和成本- 生产要素的分类和应用。
- 不同生产要素对成本的影响。
2. 成本与产量的关系- 固定成本和可变成本的概念。
- 边际成本和平均成本之间的关系。
3. 边际产量和法则- 边际产量递减法则的解释和应用。
- 边际产量与成本之间的关系。
4. 市场结构- 垄断、寡头垄断、垄断竞争和完全竞争的概念和特征。
- 不同市场结构对价格和产量的影响。
第四部分：市场失灵1. 外部性- 外部性的定义和分类。
- 正向和负向外部性对市场效率的影响。
2. 公共物品- 公共物品的定义和特征。
- 公共物品的提供方式和问题。
3. 不完全竞争市场- 垄断和寡头垄断市场对社会福利的影响。
AP微观经济学市场结构部分20道精华题目(北京王府学校 傅莹老师)
AP微观经济学市场结构部分20道精华题目（傅莹老师）Questions 1-2 refer to the graph below1. If the firm produces 10 units of output, its economic profits will equal (2012,第8题，AP微观, Answer: B)(A) 0(B) $50(C) $100(D) $150(E) $2002. Which of the following is most likely to occur if the firm increases production beyond 10 units? (2012,第9题，AP微观, Answer: C)(A) Consumers would be willing to purchase more than 10 units at the price of $20 per unit(B) The firm would definitely experience a loss.(C) The firm would have to lower its price to sell more than 10 units.(D) The firm’s average cost of production would initially increase.(E) The firm’s profits would increase.3. Which of the following statements about a constant-cost perfectly competitive industry in long-run equilibrium must be true? . (2012,第10题，AP微观, Answer: A)(A) An increase in demand will cause no change in the long-run equilibrium price.(B) An increase in demand will cause no change in the long-run equilibrium quantity.(C) The long-run supply curve is upward sloping.(D) The long-run supply curve is perfectly inelastic.(E) The total cost of production remains the same as output increases.4. In which of the following market structures do firms recognize their mutual interdependence? (2012,第11题，AP微观, Answer: A)(A) Oligopoly(B) Monopoly(C) Perfect competition(D) Unregulated natural monopoly(E) Monopsony5. Assume that a profit-maximizing firm is perfectly competitive in both the output and the factor Markets and is at its long-run equilibrium. The firm’s output is 100 units, its total revenue is $600.00, and the fixed cost of production is $50.00. Based on this information, which of the following is true for the firm? (2012,第12题，AP微观, Answer: E)(A) Its marginal cost is $5.50, and its average total cost is $5.50.(B) Its marginal cost is $5.50, and its average variable cost is $5.50.(C) Its marginal cost is $6.00, and its average total cost is $5.50.(D) Its marginal cost is $6.00, and its average fixed cost is $5.50.(E) Its marginal cost is $6.00, and its average variable cost is $5.50.6. Within the range of market demand, which of the following is consistent with the conditions? of a natural monopoly? (2012, 第21题，AP微观, Answer: C)(A) Long-run total cost decreases as output increases.(B) Long-run average total cost remains constant as output increases.(C) Long-run average total cost decreases as output increases.(D) Marginal cost exceeds average cost.(E) Setting price equal to marginal cost will maximize profits.7. A constant-cost, perfectly competitive gadget industry is in long-run equilibrium. An increase in the number of consumers of gadgets will most likely result in (2012,第23题，AP微观, Answer: D)(A) higher short-run and long-run prices for gadgets(B) reduced short-run profits, followed by the exit of some firms(C) an upward shift in all short-run cost curves, followed by a higher long-run price for gadgets(D) a higher short-run price for gadgets, followed by an increase in the quantity produced(E) a decrease in the demand for gadgets, followed by a decrease in the supply of gadgets8. The profit-maximizing firm depicted in the graph above should (2012,第24题，AP 微观, Answer: A)(A) exit if conditions do not improve in the long run(B) produce the output that minimizes average total cost(C) increase price to maximize profits(D) increase output to maximize profits(E) use less capital and more labor to reduce cost9. The graph above shows the short-run cost curves of a firm in a perfectly competitive market. Which of the following are true at the firm’s profit maximizing output level? (2012,第38题，AP微观, Answer: C)I. Price exceeds average total cost.II. Economic profits are zero.III. Marginal cost equals average total cost.IV. New firms are likely to enter the market in the long run.(A) I and II only(B) I and III only(C) I and IV only(D) II, III, and IV only(E) I, II, III, and IV10. Which of the following best describes an oligopolistic market? (2012,第39题，AP微观, Answer: C)(A) Many sellers with identical products and no barriers to entry(B) Many sellers, each with a clearly differentiated product, and no barriers to Entry(C) A few competing sellers with similar products and high barriers to entry(D) A few competing sellers of identical products and no barriers to entry(E) No competition among sellers and high barriers to entry11. The payoff matrix below shows the per-unit profits associated with the production strategies of two utility companies, UA and UB. Each firm has two choices: to reduce production by 10 percent or by 20 percent. The first entry in each cell indicates the profits to UA, and the second, the profits to UB. (2012,第39题，AP微观, Answer: B)Based on the information, and assuming no cooperation, which of the following statements is true?(A) Neither company has a dominant strategy.(B) Both companies have an incentive to reduce production by 10%.(C) Both companies have an incentive to reduce production by 20%.(D) Only UA has an incentive to reduce production by 20%.(E) Only UB has an incentive to reduce production by 20%.12. In order to minimize short-run losses, a profit maximizing firm will necessarily shut down production under which of the following conditions? (2012,第41题，AP 微观, Answer: D)(A) Total revenue is less than total cost.(B) Marginal cost is greater than average total cost.(C) Marginal cost is less than marginal revenue.(D) Average revenue is less than average variable cost.(E) Average revenue is less than average total cost.13. Most economists argue that a monopoly is inefficient because it (2012,第44题，AP微观, Answer: B)(A) has no incentive to minimize its costs(B) produces too little output and sets a price above marginal cost(C) earns too much profit by charging consumers any price it wants(D) produces too much output and thus wastes scarce resources(E) usually produces unsafe products if not regulated by government14. The graph above shows the total revenue and total cost curves for a firm in which type of market structure and what is the profit-maximizing quantity? (2012,第52题，AP微观, Answer: D)Market Structure Quantity(A) Monopoly Q2(B) Monopoly Q3(C) Perfect Competition Q1(D) Perfect Competition Q3(E) Perfect Competition Q415. A monopolistically competitive firm advertises in order to (2012,第57题，AP微观, Answer: B)(A) shift the demand curve for its product to the left(B) make the demand for its product less price elastic(C) make its product more similar to its competitors’(D) increase its positive externalities(E) reduce the industry’s barriers to entry16. Instead of being employed at a printing company at a salary of $25,000 per year, Sally starts her own printing firm. Rather than renting a building that she owns to someone else for $10,000 per year, she uses it as the location for her company. Her costs for workers, materials, advertising, and energy during her first year are $125,000. If the total revenue from her printing company is $155,000, her total economic profit is (2012,第28题，AP微观, Answer: A)(A) -$5,000(B) $5,000(C) $20,000(D) $30,000(E) $120,00017. The use of game theory to explain strategic behavior among firms is most associated with which of the following market structures? (2013, 第9题，AP微观. Answer:C)(A) Perfect competition(B) Monopolistic competition(C) Oligopoly(D) Monopoly(E) Monopsony18. All of the following are essential characteristics of a perfectly competitive industry EXCEPT: (2013, 第10题，AP微观. Answer:D)(A) All products produced by the firms in the industry are homogeneous.(B) All firms in the industry are price takers.(C) All consumers and firms are completely aware of the prices at which transactions take place in theindustry.(D) There are barriers to entry into and exit from the industry.(E) Price is equal to marginal revenue for every firm in the industry.19. Which of the following indicates that a perfectly competitive firm is in long-run equilibrium? (2013, 第13题，AP微观. Answer:C)(A) Price equals marginal cost.(B) Price equals average revenue.(C) Price equals marginal cost, which equals average total cost.(D) Price equals average revenue, which equals marginal revenue.(E) Price equals average fixed cost.20. If a perfectly competitive firm is producing where marginal cost is rising and greater than marginal revenue, to maximize profits it should (2013, 第16题，AP 微观. Answer:B)(A) increase the level of production(B) decrease the level of production(C) maintain current level of production(D) increase price(E) decrease price。
AP经济学深度解析
AP经济学深度解析AP课程规划中，经济学有两门独立的考试：一是微观经济学，二是宏观经济学。
每门考试设立的对象，都是有志于在高中阶段完成大学第一学期入门课程学习的有条件的学生。
每门考试都要求至少一学期的大学程度的学习。
在同一年中，学生可以只参加一门考试或两门都参加。
每门考试都各有一个分数。
课程描述和两门考试中所涉及的材料，都是由AP经济学课程发展委员会的经济学家委员们挑选出来的。
为了该课程与考试的设立，委员会调查了200多所高校的经济学系，这些高校的经济学系学生获得的AP考试得分都是最高的。
依据他们获得的具有代表性的大学入门课程的内容，委员会确立了课程大纲，至于考试中的多项选择题部分所涉及的大纲内容，都已在学习程度对等的经济学课程的大学学生中进行了预先测验。
AP课程描述与考试能够代表大学课程，因此被认为是适用于考查微观与宏观经济学入门课程的技能与知识。
大学课程微观经济学或宏观经济学的大学入门课程通常教授一个学期。
许多大学在这两个学科领域都设有多种课程。
AP课程大纲并未详细体现微观经济学或宏观经济学的任何一门大学课程；AP经济学课程的目的是让学生能从中获得与一般大学入门性微观经济学或宏观经济学方面课程相一致的学习经验。
AP微观经济学课程AP微观经济学课程的设置是为了使学生了解经济学原理。
个体决策者，无论是消费者还是生产者，在经济体制下都需要运用这些经济学原理才能发挥作用。
该课程特别强调产品市场的性质与功能，也研究了要素市场和政府在促进经济高效、公平运作中的作用。
AP宏观经济学课程AP宏观经济学课程的设置目的是：帮助学生深入了解用于研究经济体制整体的经济学原理。
该课程特别注重国民收入和价格水平的确定等内容，同时，也能帮助学生更熟悉经济绩效评估指标、财政部门、稳定政策、经济增长和国际经济学等内容。
考试微观经济学与宏观AP经济学课程考试各需要两个多小时。
每门考试都包含70分钟的多项选择部分和60分钟的自由回答题部分。
AP微观经济学考试内容
AP微观经济学考试内容三立AP频道为大家带来AP微观经济学考试内容一文，希望对大家AP备考有所帮助。
AP微观经济学考查内容：(1) 经济学基本概念(8-14%)(2) 供给、需求与市场均衡(15-20%)(3) 消费者行为(5-10%)(4) 生产者产量以及成本(10-15%)(5) 市场结构(完全竞争、垄断、垄断竞争和寡头)(25-35%)(6) 要素市场(10-18%)(7) 市场失灵和政府行为(12-18%)AP微观经济学分为选择题以及简答题两个部分。
选择题总共为60道，时间为70分钟，分数占比为2/3;简答题3道，时间为50分钟，分数占比为1/3。
卷面分数为90分，一般来说，学生需要考到70分以上，才有可能获得5分，即优秀水平，可见要求相对较高。
第一：微观经济学基本概念(Basic Concepts)1. 经济学研究的问题?重点：稀缺性(Scarcity),金钱稀缺+时间稀缺。
合理利用有限的资源(Limited Resources)去满足无限的需求(Unlimited Wants)。
2. 机会成本(Opportunity Cost)的定义重点：定义。
机会成本是指为了得到某种东西而所要放弃最好的选择的成本。
考试中必考某件事的机会成本的选择题。
3. 机会成本递增原则(Law of Increasing Opportunity Cost)重点：定义。
是指在生产两种产品的条件下，为增加其中一种产品的生产量而不得不放弃的另外一种产品的价值,那么生产成本不是不变，而是不断增加。
4. 生产可能性曲线(Production Possibilities Frontier)重点：4.1 搞清楚PPF曲线线上的点，曲线内部的点，曲线外部的点各自有什么意义。
4.2 搞清楚何时PPF是曲线还是直线(资源可以完美替代去生产另一种产品)。
5. 绝对优势(Absolute advantage)，比较优势(Comparative advantage)，专门化(Specialization)重点：5.1 绝对优势和比较优势各自比较的是什么：Absolute Cost计算的是生产某物品的成本,Comparative Cost计算的是生产某物品的机会成本。
考前必看干货：AP微观经济考试重点
考前必看干货：AP微观经济考试重点离AP考试的时间越来越近。
突然发现留学党们不是在崩溃复习中，就是在崩溃复习的路上。
所以今天为大家献上AP微观经济复习提纲，速度转走吧!第一章：基础微观经济学概念(Basic Concepts)1. 为什么要学习经济学?重点：定义。
合理利用有限的资源去满足无限的需求。
(Unlimited wants, limited resource)2. 机会成本(opportunity cost)的定义重点：定义。
得到某种东西而所要放弃另一些东西的最大价值;也可以理解为在面临多方案择一决策时，被舍弃的选项中的最高价值者是本次决策的机会成本。
考试中必考某件事的机会成本的选择题。
3. 机会成本递增原则(law of increasing opportunity cost)重点：定义。
在既定的经济资源和生产技术条件下，每增加一单位一种产品的产量所产生的机会成本递增，即要放弃更多其他产品的产量。
结合5中的PPC 曲线加强理解。
4. 边际分析(marginal analysis)重点：当边际利益(marginal benefit,简称MB)=边际成本(marginal cost,简称MC),属于决定做不做某事的临界点。
当MB>MC，去做某事。
当MB5. 生产可能性曲线(production possibilities curve/frontier)重点：5.1搞清楚PPC曲线线上的点，曲线内部的点，曲线外部的点各自有什么意义。
5.2 搞清楚何时PPC是直线：资源可以完美替代去生产另一种产品5.3 使PPC曲线向外扩展的三个要素：科技进步，资源质量数量提高，贸易6. 绝对优势，比较优势，专精(absolute advantage, comparative advantage, specialization)重点：6.1 绝对优势和比较优势各自比较的是什么：AA计算的是生产某物品的unit/cost, CA计算的是生产某物品的unit/opportunity cost6.2 学会计算comparative advantage6.3 为什么要specialization和trade7. 市场系统模型(market system)重点：说出自由市场经济体制(free economics), 计划经济体制(command economics), 复合经济体制(mixed economics)三种市场模型的特点。
AP微观经济学复习知识点
AP微观经济学复习知识点AP微观经济学复习知识点【考前必看】，考前把知识在普及一遍，加深印象，下面请看详细内容介绍。
Trade▪Domestic price>world price→export→comparative advantage→not affect world price▪Domestic price▪When export, consumer surplus↓，producer surplus↑，total surplus↑When import, consumer surplus↑，producer surplus↓，total surplus↓▪Graph▪Tariff: decrease consumer surplus and create dwl. Graph▪Quota: a certain amount permitted to import▪Graph▪Bias about trade: (1) unfair competition: one country reduces tax on domestic products to export them, but the import country will receive the benefit from this action.(2) National security argument: use tariff to protect domestic industry. This sometimes happens in real world.(3) Jobs argument: world trade won’t cause unemployment because it is creating jobs and at the same time destroying some.(4) Infant-industry argument: infant-industry argues that they need tariff to protect to grow. However, it is hard to decide the country has comparative advantage in which industry.(5) Protection-as-a-bargain-chip argument: country A can threaten country B to decrease tariff or A will increase tariff. However this threaten won’t work as B can threaten A the same way.Cost curve▪Economic cost= accounting cost+ opportunity cost= implicit cost+ explicit cost.▪TC’=MC=VC’=VC=TC-FC▪Diminishing marginal return: hold other input constant, too much of one resource will reduce marginal return as it is inefficient.▪MC intersects ATC and AVC at their lowest point.▪There is no fixed cost in the long run▪Short run and long run ATC: The short run ATC curve is upward sloping because increase a single resource while hold the others constant will cause inefficiency. Thus the cost of producing another product is higher than average and cause the ATC to go up. However, due to definition, nothing is constant in the long run. A firm will no longer put all input into one resource while holding the others constant. Instead, the reason for long run ATC curve to slope upward is diseconomies of scale. When a company is way too big, it is hard to get everything under control and people in this firm will have different incentives which add to the difficult of keeping theorganization work. The efficiency in this case will decrease dramatically and will cause much higher to produce another unit.In the first few units, additional resources enable producers to specialize and increase the efficiency. Consequently, output increases and cause AVC to fall. Even when AVC stops falling and begins to act in opposite way, the ATC may still decrease and additional output cause AFC to decrease. It is only when AVC increases greater than AFC decreases than ATC begin to slope upward. In the long run, when input increases, people are enabled to specialize and this will increase the efficiency and cause the output to rise faster than input. Also, when number of consumer increases, the cost of some equipment that can be used by many can be divided by a larger number. Thus the cost for producing each good lowers.上海新托福精讲班多少钱？一、整体情况培训对象：英语基础薄弱大学生或未接触过托福考试的高中生培训目的：通过对托福基础听说读写的巩固及强化训练，帮助学员提高托福基础和应试技巧，顺利通过考试。
AP宏观经济学(傅莹)
1.The bank (vault cash)
2.The regional Federal Reserve Bank
A Model of Deposit Creation
• When a commercial bank receives a cash deposit, the bank’s ability to increase loans begins a chain of new loans that can lead to a multiplied increase in demand deposits and in the money supply. • The extent of the maximum multiplied increase is directly tied to the required reserve ratio.
rt
MD
$
Federal Funds Rate
Real Interest Rates and InterestSensitive Investment and Consumption r
real
r0
r1
Investments
ε0
ε1
$
Desired Expenditure
The Structure of Nominal Interest Rates
– Circulating cash falls by $1,000 (Person A’s original deposit of cash into Bank I) – While demand deposits grow by $10,000, for a net increase of $9,000
北京王府学校AP经济学资深讲师傅莹讲义
Topics About money Supply (2)
Feb sell bond $10 million to commercial bank, RRR =0.2 (1) Excess reserve for the bank : decrease $10 million (2) Demand deposit : no change (3) the maximum amount of change of money supply: decrease 50 million
Topics About money Supply (3)
Kim deposit $10 million of cash from her pocket into her checking account, RRR=0.2, no excess reserve (1) The maximum dollar amount the commercial bank can initially lend 10* 0.8= 8 million (2) the maximum total change in demand deposit in the banking system is 10+8 * 5= 50 min the money supply: 50-10= 40 million (4) the immediate impact of the deposit on the money supply : no immediate impact since checking account can be drawn soon.
Thanks for your participation.
谢谢您的观看!
北京王府学校
ap宏观经济学知识点
ap宏观经济学知识点【篇一：ap宏观经济学知识点】开考科目：详情查看请点击：【】【新航道提供免费服务，优先抢考位，如需代报名，详情查看：，或者在线咨询我们的老师】六、 ap经济学考试中的十三大要点1 、fundamentals of economic analysisscarce resourcesproduction possibilitiesfunctions of economic systems2、 demand, supply, market equilibrium, and welfare analysis demandsupplymarket equilibriumwelfare analysis3、elasticity, microeconomic policy, and consumer theory elasticitymicroeconomic policy and applications of elasticity consumer choice4、the firm, profit, and the costs of productionfirms, opportunity costs, and profitsproduction and cost5、market structures, perfect competition, monopoly, and things betweenperfect competitionmonopolymonopolistic competitionoligopoly6、factor marketsfactor demandleast-cost hiring of multiple inputsfactor supply and market equilibriumimperfect competition in product and factor markets7、public goods, externalities, and the role of government public goods and spillover benefitspollution and spillover costsincome distribution and tax structures8、 macroeconomic measures of performancethe circular flow modelaccounting for output and incomeinflation and the consumer price indexunemployment9、 consumption, saving, investment, and the multiplier consumption and savinginvestmentthe multiplier effect10、aggregate demand and aggregate supplyaggregate demandaggregate supplymacroeconomic equilibriumthe trade-off between inflation and unemployment11、fiscal policy, economic growth, and productivity expansionary and contractionary fiscal policydifficulties of fiscal policyeconomic growth and productivity12、money, banking, and monetary policymoney and financial assetsfractional reserve banking and money creationmonetary policy13、 international tradecomparative advantage and gains from tradebalance of paymentsforeign exchange ratestrade barriers【篇二：ap宏观经济学知识点】阅读，只需一秒。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
AP经济学的重点和难点知识（北京王府学校傅莹）1. AP经济学中边际的概念AP经济学中边际的概念 Margin在AP微观经济学中，有一个学生比较不容易理解的概念，就是边际的概念。
在历年的AP微观经济学考试中，不管是单选题还是简答题都会考到边际的概念。
边际（Margin）主要指微小的变化量，在数学上是导数的概念。
在现实生活中，我们作为个体的每个人都要面临边际的抉择，比如我们在AP 经济学考试的前一天晚，有一个精彩的电影我特别想看。
这时候我就要比较一下，如果我舍弃这一小时的电影去学习，是否能够让我从原来的4分变成5分，如果这种比较后，我觉得用看电影的这多的两个小时学习，我能提高很多，我会放弃看电影的选择。
以上是一种边际决策，即我是否要在考试前多看两小时的书。
这种分析是建立在已经看了若干小时书的前提下，比较是否应该在多付出那么一点点。
在厂商的生产决策中，也经常面临边际决策。
厂商是否在原有生产量的基础上多生产1个单位的产品。
这时候厂商将会比较增加1个单位产品增加的收益（边际收益Marginal Revenue）和增加1个单位产品增加的成本（边际成本Marginal Cost，主要是多付给一个工人的工资）。
如果边际收益（Marginal Revenue）大于边际成本(Marginal Cost)，则继续生产。
反之，则不会在继续生产，因为这时候如果继续生产，额外的投入（Marginal Cost）会大于额外的收益（Marginal Revenue），厂商多生产得不偿失。
与边际有关的概念在AP经济学考试中常出现。
主要有以下内容：（1）Marginal Revenue （MR）（2）Marginal Benefit （MB）（3）Marginal Cost （MC）（4）Marginal Private Benefit （MPB）（5）Marginal External Benefit （MEB）（6）Marginal Social Benefit （MSB）（7）Marginal Private Cost （MPC）（8）Marginal External Cost （MEC）（9）Marginal Social Cost （MSC）（10）Marginal Utility （MU）（11）Marginal Product （MP）（12）Marginal Product of Labor (MPL)（13）Marginal Product of Capital (MPc)（14）Marginal Resource Cost (MRC)（15）Marginal Revenue Product (MRP)还有几个与Marginal有关的公式：（1）资源分配最有效： MB= MC（2）企业利润最大化的产量: MR=MC（3）企业收益（total Revenue）最大化: MR=0（4）MSC=MPC+ MEC（5）MSB=MPB+ MEB（6）Total Utility最大化： MUA/ PA= MUB/PB（7）使用资源成本最小化： MPC/ PC= MPL/PL（8） MRP=MP * P（9）完全竞争的劳动力市场 MRP= MRC2.经济学中的成本、收益和利润我们在AP考试中经常会看到题目会问经济利润（Economic Profit）和正常利润（Normal Profit）。
经济学中经济利润（Economic Profit）不同于会计利润（Accounting Profit）。
会计利润（Accounting Profit）= 收入（Revenue）- 显性成本（explicit cost）经济利润（Economic Profit）= 收入（Revenue）- 显性成本（explicit cost）- 隐性成本（Explicit Cost）。
正常利润(Normal profit)是指企业主如果把资源用于其它相同风险的事业所可能得到的收入，它属于机会成本性质。
在西方经济学中,正常利润指厂商对自己所提供的企业家才能的报酬及支付,正常利润是隐性成本的一部分。
正常利润通常是指厂商对自己所提供的企业家才能的报酬支付。
从机会成本的角度说，它是厂商生产成本的一部分，以隐成本计入成本。
利润分为正常利润与超额利润（即经济利润）。
正常利润是企业家才能的价格，也是企业家才能这种生产要素所得到的收入。
它包括在成本之中，其性质与工资相类似，也是由企业家才能的需求与供给所决定的。
超额利润是指超过正常利润的那部分利润，又称为经济利润。
3. 市场结构(1) 完全竞争的市场( Perfect Competitive market)完全竞争的几大特点：Many sellers sell identical products to many buyers;No barriers, meaning firms freely enter and exit;Price is taken from the market, and the firm can sell as many products as they want at this price;Demand is perfectly elastic (horizontal line)，Price = marginal revenue = average revenueHave allocative efficency （price = marginal cost)利润最大化时是水平的demand curve 和上升的marginal cost 的相交点，向下和X轴相加的点是利润最大化时的产量；利润最大化时的产量那条垂直线和average total cost 相交，再做水平线与Y轴相交，则是平均成本点。
由demand curve (代表selling price)，平均成本价和产量，即可得出是economic profit (平均成本价在卖价下面），或是亏损（平均成本价在卖价上面）。
不论任何一种市场类型，要找利润最大化的产量，一定要先找到marginal revenue = marginal cost 的点，即MR 和MC的相交点，再向下与X轴相交于利润最大化时的产量短期(short-run)时几个重要的点：Shut down position (price = variable cost)Break even position (price = average total cost)Profit maximizing position (price = marginal cost)长期(long-run)时几个重要的点：Economic profit = 0 (making normal profit, accounting profit is still a positive number)Price = average total cost要会画图。
长期时，水平需求曲线，上扬的边际成本曲线和U型的平均成本曲线相交于一点。
会画完全竞争市场firm 和 market的 side by side graph. 别忘了，firm 的价格是从市场上拿来的。
作为这个产业中成千上万卖者中的一个，firm 没有这个市场能力去改变调整价格。
所以需求曲线是条水平线。
(2）垄断（Monopoly）垄断的几大特点High barrier, only one seller,Has market power to make price (price maker), so demand curve is a normal slopping downward curve,Marginal revenue lies below the demand curveThere is no allocative efficency (Price > marginal cost) 要会画垄断的图，有经济利润和发生亏损的两种情况。
首先找到MR= MC的相交点，然后画一条经过此点的垂直于X轴的线，与X轴交于利润最大化时的产量；与demand curve 相交点画平行线与Y轴相交于垄断价格；与average total cost 相交点画平行线与Y轴相交于平均成本价格。
如果成本价在垄断价之上，就是亏损；如果成本价在垄断价之下，就是盈利(economic profit)。
Demand curve 和marginal cost 相交点决定了socially efficient level, 可以看到垄断者利润最大化产量小于社会效率产量。
（3）垄断竞争（Monopolistic competition）垄断竞争是处于完全竞争和垄断之间的状态，垄断的几大特点：low barriers (free entry and exit), many sellers sell differentiated products, price > marginal cost。
短期时的图形和垄断完全一样，slopping downward demand curve, marginal revenue lies below demand curve. 用同样的方法求出economic profit长期时和完全竞争一样，economic profit attracts more firms to enter, so long run， price = average total cost, economic profit = 0，与完全竞争市场不同的是长期时的产量也仍然低于社会效率产量。
(4) 寡头只要弄清楚game theory 就可以了。
如果几个寡头企业互相勾结（collude/cooperate)时其实就是垄断，能使大家都得到好处；如果各自打小算盘，导致的结果是大家都受到损害。
知道优势策略（dominant strategy）和纳什均衡（Nash equilibrium）, 市场参与者并非一定会有dominant strategy.4.财政政策和货币政策财政政策和货币政策都包括紧缩性和扩张性。
（1）财政政策扩张性财政政策（Expansionary fiscal policy）用于解决衰退，增加总需求和总产出。
政府实施扩张性财政政包括增加政府采购（Government Spending）或减少税收(taxation)或使用以上两种财政工具的组合。
紧缩性财政政策（Contractionary fiscal policy）用于解决通货膨胀，减少总需求和总产出。
政府实施紧缩性财政政策包括减少政府采购或增加税收或使用以上两种财政工具的组合。