A Level经济是一门实用性非常强的学科，培养学生的经济思维方法，解决现实问题的能力。
该科目的学习内容分为宏观经济和微观经济，对学生的综合能力、英语学术写作能力、经济类阅读积累、批判性思维能力要求都比较高。
为了帮助各位同学高效备考A Level经济，今天就给大家整理一波微观经济学的基础概念，希望大家能理解并吸收这些知识。
Society has insufficient productive resources to fulfill unlimited human wants and needs.
2. Resource allocation problem 资源分配问题
The assignment of available resources to various uses.
3. Factors in production 生产要素
Inputs used to produce goods and services.
How household sand firms make decisions and how they interact in specific markets.
Economy-wide phenomena, including inflation, unemployment, and economic growth.
6. Normative statements 规范表述
What the economy should go and what intervention should be adopted?
7. Positive statements 实证表述
What is the economy like and what happened?
Amount of goods and services produced from each hour of a worker’s time.
9. Central planning channels resource
Inputs are based on direct allocation. Centralized manner depending on the specific organization of economic institutions.(price will not have directing power).
10. Opportunity cost 机会成本
The value (not a benefit) of the choice of a best alternative lost while making a decision.
The ability of a single person or firm to unduly influence market prices.
12.production possibility frontier 生产可能性边界
Graphical representation of possible combination of two goods with constant resources and technology.
13. Absolute advantage 绝对优势
Ability of a party (anindividual, or firm, or country) to produce a greater quantity of a good, product, or service than competitors,using the same amount of resources.
14. Comparative advantage 比较优势
Agents have acomparative advantage over others in producing a particular good if they can produce that good at a lower relative opportunity cost or autarky price.
15. Asymmetric information 信息不对称
In decisions in transactions where one party has more or better information than the other. This creates an imbalance of power in transactions.
A buyer's willingness and ability to pay a price for a specific quantity of a good or service.
The percentage change in quantity demanded given a percent change in the price.
Measure the demand quantity change from the price change of relevant good.
Measure the demand quantity change from income changes.
20. Willingness to pay 支付意愿
Maximum price at or below which a consumer will definitely buy one unit of the product.
21. Consumer surplus 消费者剩余
The difference between the maximum price aconsumer is willing to pay and the actual price they do pay.
22. Law of diminishing marginal returns 边际收益递减规律
Diminishing returns is the decrease in the marginal (incremental) output of a production process as the amount of a single factor of production is incrementally increased, while the amounts of all other factors of production stay constant.(ceteris paribus)
A direct payment made to others in the course of running a business, such as wage, rent and materials.
Is the opportunity cost equal to what a firm must give up in order to use a factor of production for which it already owns and thus does not pay rent.(foregone income from choosing not to work).
25. Accounting profit 会计利润
Total revenue – total explicit cost.
Total revenue – total cost (explicit+implicit)；Economic profit =0: normal economic profit
In the goods market, supply is the amount of a product that producers are willing to sell at various given prices when all other factors are held constant. (ceteris paribus).
28. Producer surplus 生产者剩余
The difference between the minimum price a producer is willing to sell and the actual price they do to sell.
Economic equilibrium is a state where economic forces such as supply and demand are balanced. In goods market, equilibrium price stands for aprice that sellers sold the same amount that buyers want to buy (clearance).
30. Market structure 市场结构
Characterization of how market operates differently
What do buyers know about product?
How products differ from each other?
Is producer easy to entry or exit?
31. Perfect competition 完全竞争
There are numerous sellers and buyers；Both are price taker in market；Free move for producer；Homogeneous products
Unique supplier in the market；No substitutes；Price maker
Two or several supplier；Barriers to entry；Product differentiation or homogeneous；Non-price competition；Interdependence
34. Monopolistic competition 垄断性竞争
Every producer has its own market demand；Good in every market is substitutes；Markets are interdependent
35. Production efficiency 生产效率
No additional output can be obtained without increasing the amount of inputs.(lowest ATC).
36. Allocative efficiency 配置效率
Any changes made to assist one person would harm another
(Equilibrium price= MC=AC)；
Market can be said to have allocative efficiency if the price of a product that the market is supplying is equal to the marginal value consumers place on it, and equals marginal cost.
Individual can be effectively exclude from use.
One individual reduce availability to others.
The cost or benefit that affects a party who did not choose to incur that cost or benefit.
40. Negative externality 负外部性
An economic activity that imposes a negative effect on an unrelated third party.
