AP Microeconomics Core Concepts Review | AP微观经济学核心考点梳理

📚 AP Microeconomics Core Concepts Review | AP微观经济学核心考点梳理

The AP Microeconomics exam tests your understanding of economic principles that apply to individual decision makers, such as consumers and firms. This article compiles the core concepts, from scarcity and opportunity cost to market structures and market failures, providing a structured review to help you excel. Each section pairs key insights in English with concise Chinese explanations, ensuring clarity for bilingual learners.

AP微观经济学考试考查你对适用于个体决策者（如消费者和企业）的经济学原理的理解。本文梳理了从稀缺性和机会成本到市场结构与市场失灵的核心概念，提供结构化复习，助你取得高分。每个部分以英文关键知识点搭配简明中文解释，确保双语学习者清晰掌握。

1. Basic Economic Concepts | 基本经济概念

Economics is the study of choice under scarcity. Scarcity means that resources are limited, forcing individuals and societies to make trade-offs. The opportunity cost of a choice is the value of the next best alternative forgone. Every decision involves opportunity cost, which is a central concept in economic analysis.

经济学研究稀缺条件下的选择。稀缺性意味着资源有限，迫使个人和社会进行权衡取舍。机会成本是所放弃的次优选择的价值。每个决策都包含机会成本，这是经济分析的核心概念。

Marginal analysis is used to make rational decisions. It involves comparing marginal benefit (MB) and marginal cost (MC). An action should be taken if MB ≥ MC. The optimal quantity is where MB = MC. This ‘marginalism’ underlies consumer and producer behavior throughout the course.

边际分析用于做出理性决策。它比较边际收益(MB)与边际成本(MC)。当MB≥MC时应采取行动，最优数量在MB=MC处。这种“边际主义”贯穿消费者和生产者的行为分析。

The production possibilities curve (PPC) illustrates scarcity, trade-offs, efficiency, and growth. Points on the curve are efficient, inside are inefficient, and outside are currently unattainable. The slope represents the opportunity cost. Economic growth shifts the PPC outward, allowing more of both goods to be produced.

生产可能性曲线(PPC)展示了稀缺、权衡、效率和增长。曲线上的点有效率，内部点无效率，外部点当前无法达到。斜率代表机会成本。经济增长使PPC向外移动，从而能生产更多两种物品。

2. Supply and Demand | 供给与需求

The law of demand states that, ceteris paribus, as the price of a good increases, quantity demanded decreases. The demand curve slopes downward. The law of supply states that as price increases, quantity supplied increases; the supply curve slopes upward. These laws are foundational to market analysis.

需求定律指出，在其他条件不变时，商品价格上升则需求量下降，需求曲线向下倾斜。供给定律指出，价格上升则供给量上升，供给曲线向上倾斜。这些定律是市场分析的基础。

Market equilibrium occurs where quantity demanded equals quantity supplied, determining the equilibrium price and quantity. If the market price is above equilibrium, a surplus arises; if below, a shortage occurs. In a free market, price adjusts to eliminate surpluses and shortages, restoring equilibrium.

市场均衡发生在需求量等于供给量处，决定了均衡价格和数量。若市场价格高于均衡，出现过剩；若低于均衡，出现短缺。在自由市场中，价格调整消除过剩和短缺，恢复均衡。

Shifts in demand are caused by changes in income, preferences, prices of related goods (substitutes and complements), expectations, and number of buyers. Shifts in supply result from changes in input prices, technology, expectations, number of sellers, and government taxes or subsidies. A shift leads to a new equilibrium.

需求变动由收入、偏好、相关商品价格（替代品和互补品）、预期及购买者数量变化引起。供给变动由投入价格、技术、预期、卖家数量及政府税收或补贴变化引起。变动导致新的均衡。

Price ceilings (legal maximum prices) set below equilibrium cause persistent shortages. Price floors (legal minimum prices) set above equilibrium cause persistent surpluses. These government interventions create inefficiency and can lead to black markets or wasteful surplus disposal.

价格上限（法定最高价）若低于均衡价，导致持续短缺。价格下限（法定最低价）高于均衡价，导致持续过剩。这些政府干预造成无效率，并可能导致黑市或过剩浪费。

3. Elasticity | 弹性

Price elasticity of demand (PED) measures the responsiveness of quantity demanded to a change in price. The formula is:

PED = %ΔQd / %ΔP

If |PED| > 1, demand is elastic; if |PED| < 1, inelastic; if |PED| = 1, unit elastic. Determinants include availability of substitutes, degree of necessity, share of the consumer's budget, and the time horizon considered.

需求的价格弹性(PED)衡量需求量对价格变动的反应程度。公式为：PED = %ΔQd / %ΔP。若|PED|>1，需求富有弹性；|PED|<1，缺乏弹性；|PED|=1，单位弹性。决定因素包括替代品的可得性、必需程度、预算份额和所考虑的时间跨度。

The total revenue test helps identify elasticity. If price and total revenue move in opposite directions, demand is elastic. If they move in the same direction, demand is inelastic. For unit elastic demand, total revenue remains constant when price changes.

总收益检验可识别弹性。若价格与总收益反向变动，需求富有弹性；若同向变动，需求缺乏弹性。对于单位弹性需求，价格变化时总收益不变。

Income elasticity of demand (YED) = %ΔQd / %Δ income. Normal goods have positive YED; inferior goods have negative YED. Cross-price elasticity of demand (XED) = %ΔQd of good A / %ΔP of good B. Substitutes have positive XED; complements have negative XED.

需求的收入弹性(YED)= %ΔQd / %Δ收入。正常品YED为正，低档品YED为负。需求的交叉弹性(XED)=A商品需求量%Δ / B商品价格%Δ。替代品XED为正，互补品XED为负。

Price elasticity of supply (PES) = %ΔQs / %ΔP. It measures how responsive quantity supplied is to price changes. PES is always positive and depends on the flexibility of producers to change output, especially the time period.

供给的价格弹性(PES)= %ΔQs / %ΔP。它衡量供给量对价格变动的反应程度。PES始终为正，

Published by TutorHao | AP Economics Revision Series | aleveler.com

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