Cambridge International AS and A Level Economics: Core Concepts and Exam Skills | 剑桥国际AS与A Level经济学：核心概念与应试技巧

📚 Cambridge International AS and A Level Economics: Core Concepts and Exam Skills | 剑桥国际AS与A Level经济学：核心概念与应试技巧

Cambridge International AS and A Level Economics develops candidates’ ability to explain, analyse and evaluate economic issues. At AS Level, learners build a strong foundation in microeconomics and macroeconomics, preparing for both multiple-choice questions and structured essays. This revision guide summarises the essential topics, common exam pitfalls and effective study techniques for the AS qualification.

剑桥国际AS与A Level经济学培养考生解释、分析和评估经济问题的能力。在AS阶段，学习者打下微观经济学和宏观经济学的坚实基础，为选择题和结构化论述题做好准备。本复习指南总结了AS资格的核心主题、常见考试误区及有效的学习技巧。

---

1. The Economic Problem and Scarcity | 经济问题与稀缺性

Economics is the study of how societies allocate scarce resources among competing uses. Scarcity means that human wants exceed the resources available to satisfy them. As a result, every economic agent – households, firms and governments – must make choices.

经济学研究社会如何在竞争性用途之间配置稀缺资源。稀缺性意味着人类的欲望超过了可用于满足这些欲望的资源。因此，每个经济主体——家庭、企业和政府——都必须做出选择。

These choices create opportunity cost, which is the value of the next best alternative forgone. In the AS exam, you must be able to identify opportunity cost in different contexts, including production possibility curves (PPCs).

这些选择产生了机会成本，即所放弃的次优选择的价值。在AS考试中，你必须能够在不同情境下识别机会成本，包括生产可能性曲线（PPC）。

---

2. Factors of Production and Opportunity Cost | 生产要素与机会成本

The four factors of production are land, labour, capital and enterprise. Land includes natural resources; labour is human effort; capital refers to manufactured goods used in production; enterprise is the willingness to take risks and organise the other factors.

四种生产要素是土地、劳动、资本和企业才能。土地包括自然资源；劳动是人的努力；资本指用于生产的制成品；企业才能是承担风险和组织其他要素的意愿。

Because resources are scarce, using them for one purpose means sacrificing another. This is why opportunity cost appears in nearly every AS topic, from consumer choice to government spending on healthcare versus education.

由于资源稀缺，将其用于一种用途就意味着牺牲另一种用途。这就是为什么机会成本几乎出现在每个AS主题中，从消费者选择到政府在医疗与教育之间的支出。

---

3. Demand, Supply and Market Equilibrium | 需求、供给与市场均衡

Demand is the quantity of a good or service consumers are willing and able to buy at different prices over a period of time, ceteris paribus. The demand curve slopes downward because of the substitution and income effects.

需求是在其他条件不变时，消费者在一段时间内不同价格下愿意并能够购买的商品或服务数量。由于替代效应和收入效应，需求曲线向下倾斜。

Supply is the quantity producers are willing and able to sell at different prices. The supply curve slopes upward as higher prices increase profitability and encourage firms to expand output. Market equilibrium occurs where quantity demanded equals quantity supplied.

供给是生产者愿意并能够以不同价格出售的数量。供给曲线向上倾斜，因为较高价格提高盈利能力并鼓励企业扩大产出。市场均衡出现在需求量等于供给量的位置。

---

4. Elasticity: Price, Income and Cross | 弹性：价格、收入与交叉弹性

Elasticity measures how responsive quantity demanded or supplied is to a change in price, income or another good’s price. Price elasticity of demand (PED) is calculated as:

弹性衡量需求量或供给量对价格、收入或其他商品价格变化的反应程度。需求价格弹性（PED）的计算公式为：

PED = %Δ quantity demanded ÷ %Δ price

If PED is greater than 1, demand is elastic and total revenue moves in the opposite direction to price. If PED is less than 1, demand is inelastic and total revenue moves in the same direction as price.

如果PED大于1，需求富有弹性，总收入与价格变动方向相反。如果PED小于1，需求缺乏弹性，总收入与价格变动方向相同。

Income elasticity of demand (YED) and cross elasticity of demand (XED) classify goods as normal, inferior, substitutes or complements. Price elasticity of supply (PES) measures how easily firms can respond to price changes.

需求收入弹性（YED）和需求交叉弹性（XED）将商品分为正常品、低档品、替代品或互补品。供给价格弹性（PES）衡量企业对价格变化做出反应的难易程度。

---

5. Market Failure and Externalities | 市场失灵与外部性

Market failure occurs when the price mechanism fails to allocate resources efficiently, resulting in overproduction or underproduction. Externalities are third-party costs or benefits not reflected in market prices.

市场失灵发生在价格机制未能有效配置资源，导致生产过度或生产不足时。外部性是不反映在市场价格中的第三方成本或收益。

Negative production externalities, such as air pollution from factories, cause social costs to exceed private costs. This leads to overproduction. Positive consumption externalities, such as education or vaccinations, cause social benefits to exceed private benefits, leading to underproduction.

负生产外部性如工厂的空气污染，导致社会成本超过私人成本。这导致生产过度。正消费外部性如教育或疫苗接种，导致社会收益超过私人收益，从而导致生产不足。

---

6. Government Intervention and Its Effects | 政府干预及其影响

Governments correct market failure using indirect taxes, subsidies, price controls, regulation, tradable permits and public provision. Indirect taxes on demerit goods raise private costs, while subsidies lower costs for merit goods.

政府使用间接税、补贴、价格管制、监管、可交易许可证和公共供给来纠正市场失灵。对有害品征收间接税提高私人成本，而对有益品提供补贴则降低其成本。

However, intervention can cause government failure. For example, maximum prices below equilibrium may create shortages and black markets, while minimum prices above equilibrium may generate surpluses. AS exam answers should show awareness of these trade-offs.Published by TutorHao | AS Economics Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）