Pre-U CIE Economics: Core Knowledge Review | Pre-U CIE 经济：核心知识点梳理

📚 Pre-U CIE Economics: Core Knowledge Review | Pre-U CIE 经济：核心知识点梳理

The Cambridge Pre-U Economics syllabus is designed to equip students with a deep understanding of economic theories, models, and their application to real-world contexts. This article organises the core knowledge points across microeconomics and macroeconomics, ensuring a comprehensive review for exam preparation.

剑桥Pre-U经济学课程旨在让学生深入理解经济理论、模型及其在现实世界中的应用。本文梳理了微观经济学和宏观经济学的核心知识点，为备考提供全面复习。

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

Scarcity is the fundamental economic problem that arises because resources are limited while human wants are unlimited. This forces individuals, firms, and governments to make choices and incur opportunity costs.

稀缺性是基本的经济问题，源于资源有限而人类欲望无限。这迫使个人、企业和政府做出选择并承担机会成本。

The production possibility frontier (PPF) illustrates the maximum combinations of two goods an economy can produce given its resources and technology. It demonstrates trade-offs, opportunity cost, and economic efficiency.

生产可能性边界（PPF）展示了一个经济体在给定资源和技术下能够生产的两种商品的最大组合。它体现了权衡取舍、机会成本和经济效率。

Points on the PPF are productively efficient, while points inside represent unemployed resources. Shifts of the PPF occur when resource quantity or quality changes, or when new technology is introduced.

PPF上的点代表生产有效率，内部的点表示资源未充分利用。当资源数量或质量变化、或引入新技术时，PPF会整体移动。

Economic growth can be depicted by an outward shift of the PPF, enabling higher future consumption if forgoing consumption today for investment.

经济增长可通过PPF向外移动来描绘，若今日放弃消费用于投资，未来消费即可提升。

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

The law of demand states that, ceteris paribus, as the price of a good rises, the quantity demanded falls. This inverse relationship is captured by a downward-sloping demand curve.

需求定律指出，其他条件不变下，商品价格上升则需求量下降。这种负向关系表现为向下倾斜的需求曲线。

Changes in income, tastes, prices of related goods, or expectations shift the demand curve. A movement along the curve is caused solely by a change in the good’s own price.

收入、偏好、相关商品价格或预期的变化使需求曲线移动。只有商品自身价格的变动引起沿着曲线的移动。

The law of supply indicates that, ceteris paribus, a higher price leads to a higher quantity supplied, shown by an upward-sloping supply curve. Supply shifts are driven by production costs, technology, taxes, and subsidies.

供给定律指出，其他条件不变下，价格越高供给量越大，表现为向上倾斜的供给曲线。供给移动受生产成本、技术、税收和补贴等因素驱动。

Market equilibrium occurs where the demand and supply curves intersect, determining the equilibrium price and quantity. Any imbalance creates a surplus or shortage, pushing price back towards equilibrium through market forces.

市场均衡发生在需求与供给曲线的交点，决定均衡价格与数量。任何失衡会产生过剩或短缺，通过市场力量推动价格回归均衡。

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3. Elasticity and Its Applications | 弹性及其应用

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

PED = % change in quantity demanded ÷ % change in price

需求价格弹性（PED）衡量需求量对价格变动的反应程度。

PED = 需求量变动的百分比 ÷ 价格变动的百分比

Goods with elastic demand (|PED| > 1) see a proportionately greater quantity change, often due to many substitutes or being a luxury. Inelastic demand (|PED| < 1) implies necessity or few substitutes.

弹性需求（|PED| > 1）的商品数量变动比例较大，通常因其替代品多或为奢侈品。无弹性需求（|PED| < 1）意味着必需品或替代品少。

Price elasticity of supply (PES) depends on the ease of increasing production in the short run. Factors include production time, spare capacity, and the perishability of goods.

供给价格弹性（PES）取决于短期中扩大生产的难易程度。影响因素包括生产时间、闲置产能和商品的易腐性。

Tax incidence heavily depends on relative elasticities. A more inelastic side of the market bears a larger share of the tax burden. Governments use this insight when designing excise duties.

税收负担很大程度上取决于相对弹性。市场中弹性较小的一方承担更大比例的税负。政府在设计消费税时常利用这一洞察。

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4. Market Structures and Competition | 市场结构与竞争

Perfect competition features many buyers and sellers, homogeneous products, perfect information, and no barriers to entry or exit. Firms are price takers and produce where price equals marginal cost, achieving allocative and productive efficiency in the long run.

完全竞争的市场特征包括众多买者与卖者、同质产品、完全信息以及无进出壁垒。企业是价格接受者，在价格等于边际成本处生产，长期可实现配置效率与生产效率。

Monopoly exists when a single firm dominates the market with high barriers to entry. The monopolist is a price maker, and typically restricts output to raise price, resulting in deadweight loss and higher prices for consumers.

垄断存在于单一企业主导市场且进入壁垒很高时。垄断者是价格制定者，通常会限制产量以提高价格，造成无谓损失和消费者支付更高价格。

Oligopoly is characterised by a few interdependent firms. Strategic behaviour can be modelled using game theory; kinked demand curve models explain price rigidity. Collusion, when firms cooperate to fix prices or output, is generally illegal.

寡头垄断市场由少数几家相互依存的企业构成。策略行为可用博弈论建模；弯折需求曲线模型解释了价格刚性。企业合谋以固定价格或产量的行为通常是非法的。

Monopolistic competition combines elements of monopoly and competition: many firms, differentiated products, and low barriers. In the long run, firms earn normal profits but do not achieve productive efficiency.

垄断竞争融合了垄断和竞争元素：企业众多、产品差异化、进入壁垒低。长期中企业赚取正常利润但无法达到生产效率。

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5. Market Failure and Government Intervention | 市场失灵与政府干预

Market failure occurs when the free market fails to allocate resources efficiently. Key causes are externalities, public goods, information asymmetry, and market power.

市场失灵指自由市场无法有效配置资源。主要原因包括外部性、公共物品、信息不对称和市场势力。

Negative externalities in production (e.g. pollution) cause social costs to exceed private costs. A Pigouvian tax can internalise the externality, aligning private and social costs.

生产负外部性（如污染）使社会成本超过私人成本。庇古税可将外部性内部化，使私人成本与社会成本一致。

Positive externalities (e.g. education) lead to underconsumption. A subsidy can increase consumption to the socially optimal level.

正外部性（如教育）导致消费不足。补贴可以将消费提升至社会最优水平。

Public goods are non-excludable and non-rivalrous, leading to the free-rider problem. Direct government provision is often required. Information asymmetry, such as adverse selection and moral hazard, can cause market breakdown; regulation or mandatory disclosure can mitigate these issues.

公共物品具有非排他性和非竞争性，导致搭便车问题，通常需要政府直接提供。信息不对称，如逆向选择和道德风险，可能导致市场崩溃；监管或强制信息披露可缓解这些问题。

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6. Macroeconomic Indicators and National Income | 宏观经济指标与国民收入

Gross Domestic Product (GDP) measures the total value of final goods and services produced within a country in a given period. It can be calculated using the output, income, or expenditure approaches, which are theoretically equivalent.

国内生产总值（GDP）衡量一个国家在一定时期内生产的最终产品和服务的总价值。可用产出法、收入法或支出法计算，理论上三者相等。

Inflation is the sustained increase in the general price level, measured by the Consumer Price Index (CPI). Deflation is a persistent fall in the price level. Both undermine economic stability.

通货膨胀是价格总水平的持续上涨，以消费者价格指数（CPI）衡量。通缩是价格水平持续下跌。两者均会破坏经济稳定。

Unemployment rate measures the proportion of the labour force actively seeking work but unable to find it. Types include cyclical, structural, and frictional unemployment, each with different policy implications.

失业率衡量劳动力中积极寻找工作但未能就业的比例。类型包括周期性、结构性和摩擦性失业，各有不同的政策含义。

The circular flow of income illustrates interactions between households, firms, the government, and the external sector. Injections (investment, government spending, exports) and leakages (saving, taxes, imports) determine national income equilibrium.

国民收入循环流展现家庭、企业、政府和外部部门间的互动。注入（投资、政府支出、出口）和漏出（储蓄、税收、进口）决定国民收入均衡。

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7. Aggregate Demand and Aggregate Supply | 总需求与总供给

Aggregate demand (AD) is the total planned real expenditure on goods and services produced within the economy. Its components are consumption (C), investment (I), government spending (G), and net exports (X – M).

总需求（AD）是经济体内部对产品和服务的计划实际支出总额。其组成部分为消费（C）、投资（I）、政府支出（G）和净出口（X – M）。

Short-run aggregate supply (SRAS) shows how much output firms are prepared to supply at different price levels, assuming some input prices are sticky. Long-run aggregate supply (LRAS) represents the full employment output level, which is independent of the price level.

短期总供给（SRAS）表示在部分投入价格粘性的假设下，企业在不同价格水平愿意供给的产出量。长期总供给（LRAS）代表充分就业产出水平，与价格水平无关。

Macroeconomic equilibrium occurs where AD equals SRAS. Shifts in AD can cause demand-pull inflation or recessionary gaps, while negative supply shocks lead to cost-push inflation and lower output.

宏观经济均衡发生在AD等于SRAS之处。AD的移动可导致需求拉动型通胀或衰退缺口，而负供给冲击则引发成本推动型通胀并降低产出。

In the long run, the economy tends to return to the LRAS level through wage and price adjustments, unless structural weaknesses persist.

长期中，经济会通过工资与价格调整趋向LRAS水平，除非存在持续的结构性弱点。

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8. Macroeconomic Policies | 宏观经济政策

Fiscal policy involves changes in government spending and taxation to influence AD. Expansionary fiscal policy boosts AD during a recession; contractionary policy reduces inflationary pressure.

财政政策涉及调整政府支出和税收以影响总需求。扩张性财政政策在经济衰退时刺激AD；紧缩性政策则减轻通胀压力。

Monetary policy, managed by the central bank, uses interest rates, money supply, and quantitative easing to control inflation and support growth. Lower interest rates encourage borrowing and investment; higher rates cool down an overheating economy.

货币政策由中央银行实施，使用利率、货币供应和量化宽松来控制通胀并支持增长。降低利率鼓励借贷与投资；提高利率为过热经济降温。

Supply-side policies aim to improve the productive capacity of the economy by enhancing efficiency and shifting LRAS rightwards. Examples include education and training, deregulation, and tax reforms to incentivise work and investment.

供给侧政策旨在通过提高效率、使LRAS右移来增强经济的生产能力。例子包括教育培训、放松监管以及激励工作与投资的税收改革。

The Phillips curve shows a short-run trade-off between inflation and unemployment, but the long-run Phillips curve is vertical at the natural rate of unemployment, indicating that policies cannot permanently reduce unemployment below this rate without accelerating inflation.

菲利普斯曲线显示短期中通胀与失业的权衡取舍，但长期菲利普斯曲线在自然失业率处垂直，表明政策无法在长期将失业率降至此水平以下而不引发加速通胀。

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9. International Trade and Exchange Rates | 国际贸易与汇率

The theory of comparative advantage states that countries should specialise in producing goods with the lowest opportunity cost and trade to increase overall welfare. Terms of trade impact the gains from trade.

比较优势理论指出，各国应专业化生产机会成本最低的商品并进行贸易，以提高总体福利。贸易条件影响贸易利得。

Protectionist measures, such as tariffs, quotas, and subsidies, shield domestic industries from foreign competition but can lead to inefficiency and retaliation. Justifications include infant industry protection, anti-dumping, and national security.

关税、配额、补贴等保护主义措施保护国内产业免受外国竞争，但会导致低效和报复。合理性包括保护幼稚产业、反倾销和国家安全。

Exchange rates are determined by the forces of supply and demand for currencies in floating regimes. A depreciation makes exports cheaper and imports dearer, improving the trade balance if the Marshall-Lerner condition holds.

浮动汇率制下汇率由货币供求决定。本币贬值使出口更便宜、进口更昂贵，若马歇尔-勒纳条件成立可改善贸易收支。

Fixed or managed exchange rates require central bank intervention and reserves. The balance of payments records all transactions between a country and the rest of the world, comprising the current, capital, and financial accounts.

固定或管理汇率需要央行干预和外汇储备。国际收支记录一国与世界其他地区的所有交易，包括经常账户、资本账户和金融账户。

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10. Economic Development and Sustainability | 经济发展与可持续性

Economic growth refers to an increase in a country’s real GDP over time, while economic development is a broader concept encompassing improvements in living standards, poverty reduction, and human capabilities, often measured by the Human Development Index (HDI).

经济增长指一国实际GDP随时间增长，而经济发展是更广泛的概念，涵盖生活水平改善、减贫和人的能力提升，通常以人类发展指数（HDI）衡量。

Barriers to development include low savings and investment, poor infrastructure, political instability, and adverse terms of trade. The Harrod-Domar model links growth to savings and capital-output ratios, while the Lewis model describes structural transformation from agriculture to industry.

发展障碍包括储蓄和投资低、基础设施差、政治不稳定和不利的贸易条件。哈罗德-多马模型将增长与储蓄及资本-产出比联系，刘易斯模型则描述了从农业向工业的结构转型。

Sustainable development meets present needs without compromising future generations’ ability to meet their own needs. It balances economic, social, and environmental objectives.

可持续发展在满足当代需求的同时不损害后代满足其需求的能力。它平衡经济、社会和环境目标。

Policies to promote development include investment in education and health, microfinance, fair trade initiatives, and debt relief. Addressing climate change through carbon pricing and green technology is increasingly central to sustainable growth.

促进发展的政策包括教育和卫生投资、小额信贷、公平贸易倡议和债务减免。通过碳定价和绿色技术应对气候变化对可持续增长日益重要。

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Published by TutorHao | Economics Revision Series | aleveler.com

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