2013年微观经济学复习提纲

Outline for Reviewing Microeconomics (2013)adverse selection：is a term used in economics, insurance, risk management, and statistics. It refers to a market process in which undesired results occur when buyers and sellers have asymmetric information (access to different information); the "bad" products or services are more likely to be selected. For example, a bank that sets one price for all of its chequing account customers runs the risk of being adversely selected against by its low-balance, high-activity (and hence least profitable) customers. Two ways to model adverse selection are to employ signaling games and screening games.budget Line：a line indicating the combination of commodities that a consumer can buy with a given income at a given set of prices. Also sometimes called the budget of constraint.Coase Theorem科斯定理: The theorem states that if trade in an externality is possible and there are no transaction costs, bargaining will lead to an efficient outcome regardless of the initial allocation of property. P93. Complements: goods are complements if an increase in the price of one decreases the demand for the other. consumer surplus: a gap between the total utility of a good and its total market value is called consumer surplus.demand curve: a schedule or curve showing the quantity of a good that buyers would purchase at each price, other things equal. Normally a demand curve has price on the vertical or Y axis and quantity demanded on the horizontal or X axis. Also see change in demand vs. change in quantity demanded.diminishing marginal utility: the low which says that as more and more of any one commodity is consumed, its marginal utility declines.Economies of scale: arise when an increase in all inputs leads to a more-than-proportional increase in the level of output.economies of scope: economies of producing multiple goods or service. Thus economies of scope exist if it is cheaper to produce good X and good Y together rather than separately.engel curve：an Engel curve shows how the quantity demanded of a good or service changes as the consumer's income level changes. In order to be consistent with the standard model of utility-maximization, Engel curves must possess certain properties.externality: activities that affect others for better or worse, without those others paying or being compensated for the activity. Externalities exist when private costs or benefits do not equal social costs or benefits. The two major species are external economies and external diseconomies.first-degree price discrimination:fixed cos t: represents the total dollar expense needed to produce each level of output q. TC rises as q. rises.indifference curve: a curve drawn on a graph whose two axes measure amounts of different goods consumed. Each point on one curve(indicating different combinations of the two goods) yields exactly the same level of satisfaction for a given consumer.Isocost line: in economics an isocost line shows all combinations of inputs which cost the same total amount.isoquant：is a contour line drawn through the set of points at which the same quantity of output is produced while changing the quantities of two or more inputs.marginal benefit: the additional revenue a firm would earn if it sold 1 extra unit of output. In perfect competition, MR equals price. Under imperfect competition, MR is less than price because, in order to sell the extra unit, the price must be reduced on all prior units sold.marginal cost: denotes the extra or additional cost of producing 1 extra unit of output. marginal rate of substitution: is the rate at which a consumer is ready to give up one good in exchange for another good while maintaining the same level of utility. marginal rate of technical substitution: In economic theory, the Marginal Rate of Technical Substitution(MRTS) - or Technical Rate of Substitution(TRS) - is theamount by which the quantity of one input has to be reduced () when one extraunit of another input is used (), so that output remains constant ().Marginal utility: the expression “marginal”is a key term in economics and always means “additional” or “extra.” Marginal utility denotes the additional utility you get from the consumption of an additional unit of a commodity.market failure: an imperfection in a price system that prevents an efficient allocation of resources. Important examples are externalities and imperfect competition.moral hazard: Nobel laureate Paul Krugman explains moral hazard as "any situation in which one person makes the decision about how much risk to take, while someone else bears the cost if things go badly.natural monopoly：is a company that experiences increasing returns to scale over the relevant range of output and relatively high fixed costs.opportunity cost: is the value of the most valuable good or service forgone.price discrimination: is the practice of charging different prices for the same service to different customers.price elasticity of demand: measures how much the quantity demanded of a good changes when its price changes. The precise definition of price elasticity is the percentage change in quantity demanded divided by the percentage change in price. producer surplus: includes the rent and profits to firms and owners of specialized inputs in the industry and indicates the excess of revenues over cost of production. production possibilities frontier：the PPF shows the options open to an individual, household, or firm in a two-good world. By definition, each point on the curve is productively efficient, but, given the nature of market demand, some points will be more profitable than others. Equilibrium for a firm will be the combination of outputs on the PPF that is most profitable.public goods: are commodities which can be enjoyed by everyone and form which no one can be excluded.returns to scale：diminishing returns and marginal products refer to the response of output to an increase of a single input when all other inputs are held constant.supply curve: for a commodity shows the relationship between its market produce and the amount of that commodity that producers are willing to produce and sell, other things held constant.third-degree price discrimination：In third degree price discrimination, price varies by attributes such as location[6]or by customer segment, or in the most extreme case, by the individual customer's identity; where the attribute in question is used as a proxy for ability/willingness to pay.variable cost: represents expenses that vary with the level of output---such as raw materials, wages, and fuel---and includes all costs that are not fixed.。