📚 Year 11 CIE Economics: Core Knowledge Review | Year 11 CIE 经济：核心知识点梳理
This article covers the essential topics in CIE IGCSE Economics, providing a structured revision resource for Year 11 students. Each section pairs concise English explanations with Chinese translations to reinforce understanding and bilingual competence.
本文梳理了 CIE IGCSE 经济学的核心知识点，为 Year 11 学生提供结构化复习资料。每个小节均配以简洁的英文解释和中文翻译，帮助巩固理解并提升双语能力。
1. Scarcity, Choice and Resource Allocation | 稀缺性、选择与资源配置
The basic economic problem arises because resources are scarce while human wants are infinite. This forces all economic agents—individuals, firms and governments—to make choices. Every choice involves an opportunity cost, which is the value of the next best alternative forgone.
基本经济问题源于资源的稀缺性与人类欲望的无限性。这迫使所有经济主体（个人、企业和政府）做出选择。每一个选择都涉及机会成本，即所放弃的次优选项的价值。
To visualise trade-offs, economists use the Production Possibility Curve (PPC). A PPC shows the maximum possible output combinations of two goods with given resources and technology. Points inside the curve indicate inefficiency, while points outside are unattainable. Economic growth shifts the PPC outward.
经济学家用生产可能性曲线（PPC）来展示权衡取舍。PPC 表示在给定资源和技术下，两种商品的最大可能产出组合。曲线内的点表示无效率，曲线外的点无法实现。经济增长会使 PPC 向外移动。
Every economy must answer three fundamental questions: What to produce? How to produce? For whom to produce? These are addressed by different economic systems—market, planned and mixed.
每个经济体制都必须回答三个基本问题：生产什么？如何生产？为谁生产？不同的经济体系——市场经济、计划经济和混合经济——以不同方式解决这些问题。
- Market economy: resources are allocated through the price mechanism with minimal government intervention.
- Planned economy: the government makes all key decisions regarding production and distribution.
- Mixed economy: both market forces and government planning play a role; most modern economies are mixed.
- 市场经济：通过价格机制配置资源，政府干预极少。
- 计划经济：政府做出所有关于生产和分配的关键决策。
- 混合经济：市场力量与政府规划共同发挥作用；多数现代经济属于混合经济。
2. Demand, Supply and Equilibrium | 需求、供给与均衡
Demand refers to the quantity of a good or service that consumers are willing and able to buy at various prices, ceteris paribus. The law of demand states that, all else equal, as price falls, quantity demanded rises (inverse relationship). A change in price causes a movement along the demand curve, while changes in non-price factors shift the entire curve.
需求是指在其他条件不变的情况下，消费者愿意且有能力购买的商品或服务的数量。需求定律指出，其他条件不变时，价格下降，需求量上升（反向关系）。价格变动导致沿需求曲线移动，而非价格因素的变动会使整条曲线平移。
Supply represents the quantity producers are willing and able to sell at different prices. The law of supply shows a direct relationship: higher prices incentivise greater quantity supplied. Factors such as production costs, technology, taxes and subsidies can shift the supply curve.
供给表示生产者在不同价格下愿意且有能力出售的数量。供给定律表现为正比关系：价格越高，供给量越大。生产成本、技术、税收和补贴等因素会使供给曲线平移。
Market equilibrium occurs where the demand and supply curves intersect. At this price, quantity demanded equals quantity supplied. If market price is above equilibrium, a surplus exists; if below, a shortage occurs. The price mechanism adjusts to restore equilibrium.
市场均衡出现在需求曲线与供给曲线的交点。在该价格下，需求量等于供给量。若市场价格高于均衡价格，会出现过剩；低于均衡价格则出现短缺。价格机制会调整以恢复均衡。
3. Price Elasticity of Demand and Supply | 需求价格弹性与供给价格弹性
Price elasticity of demand (PED) measures the responsiveness of quantity demanded to a change in price. It is calculated as:
PED = %Δ Quantity Demanded / %Δ Price
需求价格弹性（PED）衡量需求量对价格变化的反应程度。计算公式为：
PED = 需求量变化百分比 / 价格变化百分比
lastic demand approaches infinity. PED influences total revenue: raising price increases revenue if demand is inelastic but reduces it if elastic.
若 PED > 1，需求富有弹性（奢侈品）；若 PED < 1，需求缺乏弹性（必需品）。完全无弹性的需求 PED = 0，完全有弹性则趋向无穷大。PED 影响总收入：如果需求缺乏弹性，提价会增加收入；若富有弹性，提价反而减少收入。
Price elasticity of supply (PES) measures how quantity supplied responds to price changes.
PES = %Δ Quantity Supplied / %Δ Price
供给价格弹性（PES）衡量供给量对价格变化的反应程度。
PES = 供给量变化百分比 / 价格变化百分比
PES depends on factors such as production time, spare capacity and the availability of raw materials. In the short run, supply is often inelastic; in the long run, it becomes more elastic.
PES 取决于生产时间、闲置产能和原材料的可获得性等因素。短期内供给通常缺乏弹性；长期内则变得更富有弹性。
4. Market Failure | 市场失灵
Market failure occurs when the free market fails to allocate resources efficiently, leading to a net welfare loss. Key causes include externalities, public goods and information asymmetry.
市场失灵指自由市场未能有效配置资源，导致净福利损失。主要原因包括外部性、公共物品和信息不对称。
Externalities are spillover effects on third parties. Negative externalities (e.g. pollution) mean social cost exceeds private cost; positive externalities (e.g. education) mean social benefit exceeds private benefit. Without intervention, goods with negative externalities are overproduced and those with positive externalities are underproduced.
外部性是对第三方的溢出效应。负外部性（如污染）意味着社会成本大于私人成本；正外部性（如教育）意味着社会收益大于私人收益。若无干预，负外部性的商品会被过量生产，正外部性的商品则生产不足。
Public goods are non-excludable and non-rivalrous (e.g. street lighting). Because people can free-ride, private firms have no incentive to provide them, resulting in under-provision. Information asymmetry, where one party has more or better information than the other, can lead to adverse selection and moral hazard.
公共物品具有非排他性和非竞争性（如路灯）。由于人们可以“搭便车”，私营企业缺乏提供公共物品的动力，导致供给不足。信息不对称指一方比另一方拥有更多或更好的信息，可能导致逆向选择和道德风险。
5. Government Intervention | 政府干预
Governments intervene to correct market failures and achieve social objectives. Common policies include indirect taxes (e.g. on cigarettes), subsidies, price controls, regulations and direct provision of goods and services.
政府干预旨在纠正市场失灵并实现社会目标。常见政策包括间接税（如对香烟征税）、补贴、价格管制、法规以及直接提供商品和服务。
An indirect tax increases production costs, shifting the supply curve leftwards, reducing output and raising price. This can internalise negative externalities. Subsidies lower costs, shift the supply curve rightwards, and encourage consumption of merit goods like healthcare.
间接税增加了生产成本，使供给曲线左移，降低产量并抬高价格，从而可以内部化负外部性。补贴则降低成本，使供给曲线右移，鼓励对医疗等有益品的消费。
Maximum prices (ceilings) are set below equilibrium to protect consumers, but can cause shortages. Minimum prices (floors) are set above equilibrium to support producers, potentially leading to surpluses. Regulations, such as bans on smoking in public places, directly restrict harmful activities.
最高限价（价格上限）设定在均衡价格以下以保护消费者，但可能导致短缺。最低限价（价格下限）设定在均衡价格以上以支持生产者，可能带来过剩。法规（如公共场所禁烟）直接限制有害行为。
6. Macroeconomic Objectives and Indicators | 宏观经济目标与指标
Most governments pursue four main macroeconomic objectives: sustainable economic growth, full employment (low unemployment), price stability (low inflation) and a stable balance of payments on the current account. These goals are measured by key indicators.
多数政府追求四大宏观经济目标：可持续的经济增长、充分就业（低失业率）、物价稳定（低通胀）以及国际收支经常账户的稳定。这些目标通过关键指标来衡量。
Gross Domestic Product (GDP) measures the total value of goods and services produced in a country over a given period. Real GDP adjusts for inflation, providing a better picture of economic growth. The unemployment rate is the percentage of the labour force actively seeking work but without a job. Inflation is measured by the Consumer Price Index (CPI), tracking changes in the price of a representative basket of goods.
国内生产总值（GDP）衡量一个国家在一定时期内生产的商品和服务的总价值。实际 GDP 剔除通胀影响，可更准确地反映经济增长。失业率指劳动力中积极寻找工作但没有工作的人所占的百分比。通胀通过消费者价格指数（CPI）衡量，追踪一篮子代表性商品的价格变化。
7. Economic Growth | 经济增长
Economic growth refers to an increase in a country's real GDP over time. It can be illustrated by an outward shift of the PPC or a rightward shift of the long-run aggregate supply curve. Growth is driven by increases in the quantity and quality of resources (land,
Published by TutorHao | Year 11 Economics Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图