📚 IB & CIE Economics: End-of-Term Revision Guide | IB & CIE 经济学期末复习提纲
As final exams approach, a structured revision of core economic concepts is essential. This guide integrates the IB and CIE Economics syllabi, covering microeconomic foundations, macroeconomic policies, international trade, and development. Use it to consolidate your knowledge, identify weak areas, and practice diagram-based and evaluative questions.
期末考试临近，系统复习核心经济学概念至关重要。本提纲整合了 IB 与 CIE 经济学课程，涵盖微观基础、宏观经济政策、国际贸易与发展。用它来巩固知识、查缺补漏，并练习基于图表和评估的题型。
1. Scarcity, Choice, and Opportunity Cost | 稀缺性、选择与机会成本
The basic economic problem arises because resources are scarce while human wants are unlimited. This forces societies to answer three fundamental questions: what to produce, how to produce, and for whom to produce. Because of scarcity, every decision involves an opportunity cost – the value of the next best alternative forgone.
基本经济问题源于资源稀缺而欲望无限。这迫使社会回答三个基本问题：生产什么、如何生产、为谁生产。由于稀缺，每个决策都涉及机会成本——所放弃的次优选项的价值。
The production possibility curve (PPC) models these trade-offs. Points on the PPC are efficient, inside are inefficient, and points outside are unattainable with current resources. An outward shift of the PPC indicates economic growth, which can result from increased factor quantity or improved technology.
生产可能性曲线（PPC）模型化了这些权衡。PPC 上的点有效率，内部点无效率，外部点以现有资源无法达到。PPC 向外移动表示经济增长，这源于要素数量增加或技术进步。
Economic systems – market, planned, and mixed – differ in how they answer the three questions. Markets allocate through price mechanisms, planned economies through government directives, and mixed economies combine both. Opportunity cost is central to cost-benefit analysis in all systems.
经济体制——市场、计划和混合——回答三个基本问题的方式不同。市场通过价格机制配置，计划通过政府指令，混合经济两者兼用。机会成本是所有体制中成本收益分析的核心。
2. Demand, Supply, and Market Equilibrium | 需求、供给与市场均衡
The law of demand states that, ceteris paribus, there is an inverse relationship between price and quantity demanded. A movement along the demand curve is caused by a price change, while shifts are driven by non-price determinants such as income, tastes, prices of substitutes/complements, and expectations.
需求定律指出，其他条件不变，价格与需求量之间存在反向关系。沿着需求曲线的移动由价格变化引起，而整体平移由非价格因素驱动，如收入、偏好、替代品/互补品价格和预期。
The law of supply indicates a direct relationship between price and quantity supplied. Shifts in supply result from changes in production costs, technology, taxes/subsidies, number of sellers, and weather (for agricultural goods). An increase in supply shifts the curve to the right.
供给定律表明价格与供给量正相关。供给曲线移动由生产成本、技术、税收/补贴、卖方数量和天气（农产品）变化引起。供给增加使曲线右移。
Market equilibrium occurs where quantity demanded equals quantity supplied at a given price. A shortage (excess demand) pushes price up; a surplus (excess supply) pushes price down. Changes in demand or supply shift the equilibrium, leading to new market-clearing prices and quantities.
市场均衡出现在需求量等于供给量时。短缺（超额需求）推动价格上升；过剩（超额供给）推动价格下降。需求或供给的变动会使均衡移动，形成新的出清价格和数量。
3. Elasticity: Price, Income, and Cross | 弹性：价格弹性、收入弹性与交叉弹性
Price elasticity of demand (PED) measures responsiveness of quantity demanded to a price change. The formula is:
PED = %ΔQd ÷ %ΔP
If |PED| ants include availability of substitutes, degree of necessity, proportion of income, and time horizon.需求价格弹性 (PED) 衡量需求量对价格变动的反应程度。公式为：
PED = %ΔQd ÷ %ΔP
如果 |PED| > 1，需求富有弹性；< 1，缺乏弹性；= 1，单位弹性。决定因素有替代品可得性、必需品程度、收入占比和时间跨度。Income elasticity of demand (YED) = %ΔQd ÷ % ds have positive YED; inferior goods have negative YED. Cross elasticity of demand (XED) = %ΔQd of good A ÷ % ndicates substitutes; negative indicates complements; near zero implies independent goods.
需求收入弹性 (YED) = %ΔQd ÷ %ΔY。正常品 YED 为正，低档品 YED 为负。交叉需求弹性 (XED) = 商品 A 需求量变化百分比 ÷ 商品 B 价格变化百分比。XED 为正说明是替代品；为负说明是互补品；接近零为独立品。
Price elasticity of supply (PES) examines producers' responsiveness. PES = %ΔQs ÷ % s); manufactured goods tend to be more elastic. Spare capacity and stock levels raise PES.
供给价格弹性 (PES) 衡量生产者反应。PES = %ΔQs ÷ %ΔP。初级产品短期 PES 常较低（时滞）；制成品弹性更大。闲置产能和库存水平会提高 PES。
4. Government Intervention: Price Controls and Taxes | 政府干预：价格管制与税收
A price ceiling (maximum price) set below equilibrium creates persistent shortage, leading to black markets, long queues, and reduced quality. Rent controls and food price caps are typical examples. A price floor (minimum price) above equilibrium causes surplus, often requiring government to purchase excess supply, as with agricultural support schemes and minimum wage.
低于均衡的价格上限会造成持续短缺，导致黑市、排长队和质量下降。租金管制和食品限价是典型例子。高于均衡的价格下限造成过剩，常需政府购买剩余供给，如农业支持政策和最低工资。
Indirect taxes (specific or ad valorem) shift the supply curve left, raising price for consumers and reducing quantity. Tax incidence depends on PED and PES: if demand is inelastic, consumers bear a larger burden. Subsidies shift supply right, lowering price and increasing output, benefiting both producers and consumers but imposing a cost on government.
间接税（从量或从价）使供给曲线左移，抬高消费者支付价格并减少数量。税负分配取决于 PED 和 PES：需求缺乏弹性时，消费者承担更大份额。补贴使供给右移，降低价格并提高产量，使生产者与消费者受益，但增加政府支出。
Governments may also use direct provision of goods and services, regulation, and information campaigns to correct market outcomes. The effectiveness depends on enforcement, administrative costs, and potential unintended consequences like market distortions.
政府还可能通过直接提供商品与服务、监管和信息宣传来纠正市场结果。效果取决于执法力度、行政成本以及可能的市场扭曲等意外后果。
5. Market Failure and Externalities | 市场失灵与外部性
Market failure occurs when the free market fails to achieve allocative efficiency. Externalities are costs or benefits experienced by third parties. Negative production externalities (e.g., pollution) cause overproduction because marginal social cost (MSC) exceeds marginal private cost (MPC). Positive consumption externalities (e.g., education) lead to underconsumption where marginal social benefit (MSB) exceeds marginal private benefit (MPB).
市场失灵是指自由市场无法实现配置效率。外部性是第三方承受的成本或收益。负生产外部性（如污染）导致生产过度，因边际社会成本 (MSC) 大于边际私人成本 (MPC)。正消费外部性（如教育）导致消费不足，因边际社会收益 (MSB) 大于边际私人收益 (MPB)。
Pigouvian taxes can internalise negative externalities by making polluters pay the external cost, shifting MSC curve down to align with MSB. Subsidies can incentivise goods with positive externalities. Tradable pollution permits (cap-and-trade) set a quantity limit and allow firms to trade allowances, achieving cost-effective emission reductions.
庇古税通过让污染者支付外部成本，使 MSC 下降至与 MSB 一致，从而将负外部性内部化。补贴可激励正外部性商品。可交易排污许可证（总量控制与交易）设定排放上限并允许企业交易配额，以成本有效的方式实现减排。
Public goods (non-rival and non-excludable) are underprovided by the market due to the free-rider problem. Information asymmetry (adverse selection and moral hazard) also causes market failure, requiring regulation or mandatory disclosure.
公共物品（非竞争性、非排他性）因搭便车问题而被市场供给不足。信息不对称（逆向选择和道德风险）也会导致市场失灵，需要监管或强制披露。
6. Macroeconomic Objectives: Inflation, Unemployment, Growth | 宏观经济目标：通胀、失业与增长
Governments pursue low and stable inflation (commonly 2%), low unemployment, sustainable economic growth, and a balanced external account. Inflation is measured by the Consumer Price Index (CPI). Demand-pull inflation arises from excess AD; cost-push inflation from rising costs (e.g., energy). Deflation can be more damaging due to delayed spending and rising real debt burden.
政府追求低而稳定的通胀（通常为2%）、低失业、可持续经济增长和外部账户平衡。通胀用消费者价格指数 (CPI) 衡量。需求拉上型通胀源于总需求过剩；成本推动型通胀源于成本上升（如能源）。通缩因推迟支出和实际债务负担加重而危害更大。
Unemployment is classified as frictional (between jobs), structural (mismatch of skills), and cyclical (due to weak demand). The natural rate of unemployment excludes cyclical unemployment. Economic growth is measured by the percentage change in real GDP; however, it may not capture well-being, inequality, or environmental degradation.
失业分为摩擦性（换工作期间）、结构性（技能不匹配）和周期性（需求疲软）。自然失业率不含周期性失业。经济增长以实际GDP变动百分比衡量，但可能未反映福祉、不平等或环境退化。
Conflicts can arise among goals: rapid growth may fuel inflation, tight monetary policy to curb inflation may raise unemployment (short-run Phillips curve trade-off). Evaluation requires considering time lags and global factors.
目标之间可能存在冲突：快速增长可能引发通胀，为抑制通胀的紧缩货币政策可能增加失业（短期菲利普斯曲线取舍）。评估需要考虑时滞和全球因素。
7. Aggregate Demand and Aggregate Supply Model | 总需求与总供给模型
Aggregate demand (AD) components:
AD = C + I + G + (X - M)
AD slopes downwards due to the wealth effect, interest rate effect, and international trade effect. Factors shifting AD include changes in consumer confidence, business expectations, fiscal policy, monetary policy, and global demand.总需求 (AD) 构成：
AD = C + I + G + (X - M)
因财富效应、利率效应和国际贸易效应，AD 曲线向下倾斜。导致 AD 移动的因素包括消费者信心、企业预期、财政政策、货币政策和全球需求的变化。Short-run aggregate supply (SRAS) is upward-sloping due to sticky wages and menu costs. Shifts in SRAS come from changes in input prices, productivity, taxes, subsidies, and supply shocks. Long-run aggregate supply (LRAS) is vertical at the full-employment level (potential output). LRAS shifts with increases in the quantity or quality of factors and technology.
短期总供给 (SRAS) 因工资粘性和菜单成本而向上倾斜。SRAS 的平移源于投入价格、生产率、税收、补贴和供给冲击的变化。长期总供给 (LRAS) 在充分就业产出水平上垂直。LRAS 随要素数量/质量改善和技术进步而右移。
AD/AS equilibrium explains output gaps. A negative output gap (recessionary) occurs when equilibrium output is below potential, creating cyclical unemployment. A positive output gap (inflationary) occurs when output exceeds potential, putting upward pressure on prices. Policymakers aim to bring the economy back to potential output.
AD/AS 均衡解释了产出缺口。当均衡产出低于潜在产出时出现负产出缺口（衰退缺口），产生周期性失业。当产出超出潜在水平时出现正产出缺口（通胀缺口），推高价格。政策制定者旨在使经济回归潜在产出。
8. Fiscal Policy and Supply-Side Policies | 财政政策与供给侧政策
Fiscal policy uses government spending and taxation to influence AD. Expansionary fiscal policy (increased G, decreased T) shifts AD right, helpful during recessions. Contractionary policy shifts AD left to cool an overheated economy. Automatic stabilizers (progressive taxes, welfare benefits) adjust without new legislation.
财政政策利用政府支出和税收影响总需求。扩张性财政政策（增加 G，减税）使 AD 右移，有助于衰退时。紧缩性政策使 AD 左移以冷却过热经济。自动稳定器（累进税、福利救济）无需新立法便可调整。
Supply-side policies aim to increase LRAS by improving the productive capacity of the economy. Interventionist policies include investment in education, infrastructure, and healthcare. Market-based policies involve deregulation, privatisation, tax reforms to incentivise work and investment, and reducing trade union power.
供给侧政策旨在通过提升经济生产能力来向右移动 LRAS。干预主义政策包括投资教育、基础设施和医疗。市场化政策涉及放松监管、私有化、激励工作与投资的税制改革，以及削弱工会力量。
Evaluating fiscal policy requires considering time lags (recognition, decision, implementation), crowding out of private investment, sustainability of public debt, and the size of the multiplier. Supply-side policies often have long gestation periods and may worsen income inequality.
评价财政政策需考虑时滞（认识、决策、执行）、挤出私人投资、公共债务可持续性以及乘数大小。供给侧政策往往见效期长，并可能加剧收入不平等。
9. Monetary Policy and Interest Rates | 货币政策与利率
Monetary policy involves the central bank controlling money supply and interest rates to achieve macroeconomic goals. A lower policy rate reduces borrowing costs, encourages consumption and investment, and shifts AD right. Higher rates tighten AD. Quantitative easing (central bank asset purchases) increases liquidity and lowers long-term interest rates when policy rates are near zero.
货币政策涉及央行通过控制货币供应和利率来实现宏观经济目标。降低政策利率减少借贷成本，鼓励消费和投资，使 AD 右移。加息则收紧总需求。量化宽松（央行购买资产）在政策利率接近零时增加流动性并压低长期利率。
ons → aggregate demand. Limitations include liquidity traps, confidence factors, and unpredictable lags.
传导机制：政策利率变动 → 市场利率 → 资产价格、预期和汇率 → 净出口和支出决策 → 总需求。局限包括流动性陷阱、信心因素和不可预测的时滞。
Inflation targeting (e.g., 2% symmetric target) provides transparency and anchors expectations. Central bank independence from political pressure is key for credibility. In small open economies, monetary policy is also influenced by global interest rates and capital flows.
通胀目标制（如对称的2%目标）提供透明度并锚定预期。央行独立于政治压力是可信度的关键。在小型开放经济中，货币政策还受全球利率和资本流动影响。
10. International Trade, Comparative Advantage, and Protectionism | 国际贸易、比较优势与保护主义
The law of comparative advantage states that countries gain from trade if they specialise in goods for which they have a lower opportunity cost. Even if one country has an absolute advantage in all goods, trade can be mutually beneficial. Diagrams using PPCs or numerical examples illustrate gains from trade.
比较优势法则指出，各国若专门生产机会成本较低的商品，便能从贸易中获益。即使一国在所有商品上均具绝对优势，贸易仍可互利。用 PPC 或数字示例的图表可说明贸易收益。
Protectionist measures include tariffs, quotas, subsidies to domestic producers, and administrative barriers. A tariff raises domestic price, reduces imports, creates deadweight loss, and generates government revenue. Quotas restrict quantity without direct revenue effect unless import licences are auctioned.
保护主义措施包括关税、配额、对国内生产者的补贴和行政壁垒。关税抬高国内价格，减少进口，产生无谓损失并带来政府收入。配额限制数量，除非拍卖进口许可证，否则无直接财政收入效应。
Arguments for protection: protect infant industries, anti-dumping, national security, safeguard jobs, and diversify the economy. Against: higher consumer prices, inefficiency, retaliation, and misallocation of global resources. The WTO promotes trade liberalisation and dispute settlement.
支持保护的理由：保护幼稚产业、反倾销、国家安全、保护就业和经济多元化。反对的理由：消费者承担高价格、低效率、报复行为和全球资源错配。世贸组织推动贸易自由化和争端解决。
11. Exchange Rates and the Balance of Payments | 汇率与国际收支
An exchange rate is the price of one currency in terms of another. Under a floating system, supply and demand for a currency determine its value. Factors include interest rates, inflation differentials, trade balances, speculation, and political stability. An appreciation makes exports dearer and imports cheaper; depreciation has the opposite effect.
汇率是一国货币用另一国货币表示的价格。浮动汇率制度下，货币的供需决定其价值。影响因素包括利率差异、通胀差异、贸易差额、投机和政治稳定性。升值使出口更贵、进口更便宜；贬值则相反。
A fixed exchange rate is pegged by the central bank using foreign reserves. Managed floats combine market forces with occasional intervention. The Marshall-Lerner condition states that a depreciation will improve the trade balance in the long run if the sum of price elasticities of demand for exports and imports is greater than one.
固定汇率由央行通过外汇储备盯住。管理浮动结合市场力量与偶尔干预。马歇尔-勒纳条件指出，若进出口需求价格弹性之和大于1，贬值长期将改善贸易差额。
The balance of payments consists of the current account (trade in goods, services, income, transfers), capital account, and financial account (FDI, portfolio investment). A current account deficit must be financed by a financial account surplus. Persistent deficits may indicate competitiveness issues and rising foreign liabilities.
国际收支包括经常账户（货物、服务、收入、转移）、资本账户和金融账户（FDI、证券投资）。经常账户逆差必须由金融账户顺差弥补。持续逆差可能反映竞争力问题与对外负债增加。
12. Development Economics and Exam Technique | 发展经济学与考试技巧
Economic development is broader than growth, encompassing living standards, health, education, and political freedoms. The Human Development Index (HDI) combines income (GNI per capita), health (life expectancy), and education (mean and expected years of schooling). Barriers to development include low savings, inadequate infrastructure, poor governance, and debt burdens.
经济发展比增长更宽泛，涵盖生活水平、健康、教育和政治自由。人类发展指数 (HDI) 综合了收入（人均GNI）、健康（预期寿命）和教育（平均和预期受教育年限）。发展障碍包括低储蓄、基础设施不足、治理不善和债务负担。
Strategies for development: inward-oriented (import substitution, protection) and outward-oriented (export-led growth, trade liberalisation). Foreign aid (bilateral, multilateral, emergency, project aid) and foreign direct investment can fill resource gaps but may create dependency or volatility. Microfinance and empowerment of women are also emphasised.
发展战略：内向型（进口替代、保护）和外向型（出口导向增长、贸易自由化）。外援（双边、多边、紧急、项目援助）和外国直接投资可填补资源缺口，但可能造成依赖或波动。小额信贷和增强女性权能也受到重视。
Exam technique: define key terms precisely, draw accurate and labelled diagrams, use chains of analysis to explain causation, and always evaluate (limitations, assumptions, stakeholder perspectives, long-run vs short-run, alternative views). Time management and addressing the specific command term (explain, evaluate, discuss) are critical.
考试技巧：精确定义关键术语，绘制准确标注的图表，运用因果链分析解释，并始终进行评估（局限性、假设、利益相关者视角、长期与短期、替代观点）。时间管理和针对具体指令词（解释、评估、讨论）作答至关重要。
Published by TutorHao | 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