曼昆的《微观经济学原理》课业笔记 英文版

Ch 1 Ten Principles of economicScarcity: the limited nature of societys resourcesEconomics: the study of how society manages its scarce resources, e.g.There are 10 principle of economic which are needed to be remember throughout.People face trade-off1. Individual(time,money) and society(efficiency vs equality). Cost of something is what your give up to get it.1. The opportunity cost of any item is whatever must be given up to obtain it. Rational people thinking at margin(effect of one additional item)1. This principle assume that everyone is rational people(made their decision base on their interests) this was addressed on Adam Smith's Wealth of Nation.People respond to incentives(诱惑物）1. This statement reveals that human psychology is a important feature in economic study.Trade can make everyone better-off1. Ex: trade of agricultural product and technology between Japan and America, it will break the law of PPF. It involved absolute advantages(low input) and comparative advantage(low opportunity cost win)Markets are usually a good way to organize economy activity. 1. Markets can balance the price. Government can sometime improve market outcome.A country's standard of living depends on its ability to produce goods and services.Price rise when government print too much money.Society Faces a Short-run Tradeoff Between Inflation and UnemploymentCh2 Thinking like a economist 2018 年 2 月 6 日 16:32Economists play two roles: 1. Scientists: try to explain the world. 2. Policy advisors: try to improve it Base on these two roles, they have two types of statement. Normative and positive. In my opinion, economists as a scientists tend to use positive statement, because positive statement is base on fact, and it is testable. Policy advisors use both positive and normative, because they need to give appropriate advice to improve overall standard of living. Therefore, they will come out with some normative statement to address their opinion, and use positive statement to prove their normative statement. Assumptions: because of the world is complex, there are two much variables, and its unlike to fit it in all one models. Therefore, economists need to make a simplify assumptions where most of the time only have two coordinates with two variables. Ex: Countries A and countries B are trading products X and Y. Ch3 Interdependence and the gains from trade 2018 年 2 月 6 日 16:28Absolute advantage: The ability to produce a good using fewer inputs than another producer Measures the cost of a good in terms of the inputs required to produce it Principle of comparative advantage Each good should be produced by the individual that has the smaller opportunity cost of producing that goodComparative advantage The ability to produce a good at a lower opportunity cost than another producer Principle of comparative advantage Each good should be produced by the individual that has the smaller opportunity cost of producing that goodnote：These idea were all following a principle that “trade“ can make everyone better-off. Therefore, in a case of international trade, two countries are willing to produce product that has opportunity cost. Off course, in international market, the less opportuntiy cost, the more completitve of the prodcut or serivce. Ch 4 Supply and demand2018 年 2 月 10 日 19:35 I.Markets and competition a. What is a market A market is a groups of buyers and sellers of a particular good or service. The buyers as a group determine the demand for the product, and the sellers as a group determine the supply of the product. Organized market: where has middle man set the price and time for exchange of product. Such as agricultural commodities. Usually have fairly large value of product being exchanged. Less organized market: Small town shops where sellers and buyers vary from time to time. The price usually decide by sellers but most of the time driven by competition. II.What is competition Competitive market: a market in which there are so many buyers and so many sellers that each has a negligible impact on the market price. There are conditions must be satisfy to be a perfect competition market. (1) The goods offered for sale are all exactly the same, and (2) the buyers and sellers are so numerous that no single buyer or seller has any influence over the market priceII.Demand a. The demand curve: the relationship bet. Price and quantity demanded Quantity demanded: any good is the amount of the good tat buyers are willing and able to purchase. Law of demand: the claim that, other things being equal, the quantity demanded of a good falls when the price of the good rises. II.Market demand VS individual demand Market demand = sum(individual demand) c.Shifts in the demand curve The market demand curve holds other things constant, but it was not always the case. There may be something happened that will change the demand curve. Either increase demand that will shift to the right or dec