📚 A-Level Economics Vocabulary by Categories | A-Level经济词汇分类总结
Mastering the precise vocabulary of Economics is a non-negotiable requirement for top marks at A-Level. This guide organizes the essential terms into logical categories, allowing you to build a structured understanding rather than memorising disconnected definitions. Use it to check your recall, sharpen your essay writing, and approach data response questions with confidence.
掌握经济学精确的词汇是A-Level拿高分不可或缺的要求。本篇指南将核心术语按逻辑分类整理，帮助你建立结构化的理解，而不是记忆零散的定义。用它来检验你的回忆、打磨论文写作，并自信地应对数据回应题。
1. Scarcity and the Basic Economic Problem | 稀缺性与基本经济问题
At the heart of Economics lies the basic economic problem: human wants are infinite, but the resources available to satisfy them are finite. This fundamental condition is called scarcity. Because of scarcity, individuals, firms, and governments must make choices, and every choice involves an opportunity cost – the value of the next best alternative foregone. The factors of production are land, labour, capital, and enterprise. A free good has no opportunity cost (e.g., air), whereas an economic good does. Consumer goods provide direct satisfaction, while capital goods are used to produce other goods.
经济学的核心是基本经济问题：人类的欲望是无限的，但满足这些欲望的资源是有限的。这种根本状况被称为稀缺性。由于稀缺性，个人、企业和政府必须做出选择，而每个选择都涉及机会成本——即所放弃的次优选择的价值。生产要素包括土地、劳动力、资本和企业家才能。免费物品没有机会成本（例如空气），而经济物品则存在机会成本。消费品提供直接满足感，而资本品用于生产其他产品。
- Positive statement – objective, testable (e.g., 'Unemployment rose to 5%'). / 实证表述 – 客观、可检验（例如'失业率升至5%'）。
- Normative statement – value-based, subjective (e.g., 'Unemployment is too high'). / 规范表述 – 基于价值判断，主观（例如'失业率太高'）。
- Ceteris paribus – 'all other things being equal'; essential for isolating causal relationships. / 其他条件不变 – 隔离因果关系的必要条件。
2. Demand, Supply and the Price Mechanism | 需求、供给与价格机制
The law of demand states that, ceteris paribus, as price falls, quantity demanded rises; the demand curve slopes downward. Movements along the demand curve are caused by price changes, while shifts of the curve are caused by changes in the conditions of demand (income, tastes, prices of substitutes/complements, population). Similarly, the law of supply indicates a positive relationship between price and quantity supplied; supply shifts when costs of production, technology, taxes, or subsidies change. The equilibrium market price clears the market. The price mechanism performs three functions: signalling, rationing, and incentivising.
需求定律指出，在其他条件不变的情况下，价格下降会导致需求量上升；需求曲线向右下方倾斜。沿需求曲线的移动由价格变化引起，而曲线的平移则由需求条件的变化引起（收入、偏好、替代品/互补品价格、人口）。同样，供给定律表明价格与供给量呈正相关；生产成本、技术、税收或补贴的变化会导致供给曲线平移。均衡市场价格使市场出清。价格机制发挥三大功能：信号传递、配给和激励。
- Consumer surplus – difference between what consumers are willing to pay and what they actually pay. / 消费者剩余 – 消费者愿意支付的价格与实际支付价格之差。
- Producer surplus – difference between the price producers receive and the minimum they are willing to accept. / 生产者剩余 – 生产者获得的价格与其愿意接受的最低价格之差。
- Inferior good – demand falls as income rises. / 低档商品 – 收入上升时需求下降。
- Normal good – demand rises with income. / 正常商品 – 需求随收入增加而上升。
- Joint supply – producing one good automatically yields another (e.g., beef and leather). / 联合供给 – 生产一种商品同时自动产出另一种（如牛肉和皮革）。
3. Elasticity | 弹性
Price elasticity of demand (PED) measures how responsive quantity demanded is to a change in price: PED = %ΔQd ÷ %ΔP. When |PED| > 1, demand is price elastic; when |PED| < 1, demand is price inelastic. Determinants include availability of substitutes, necessity vs. luxury, proportion of income, and time. Income elasticity of demand (YED) = %ΔQd ÷ %ΔY, crucial for classifying normal goods (YED > 0) and inferior goods (YED < 0). Cross-price elasticity of demand (XED) = %ΔQd of good A ÷ %ΔP of good B; positive for substitutes, negative for complements. Price elasticity of supply (PES) = %ΔQs ÷ %ΔP, depending on spare capacity, stock levels, and time periods.
需求的价格弹性 (PED) 衡量需求量对价格变化的反应程度：PED = 需求量变化百分比 ÷ 价格变化百分比。当 |PED| > 1 时，需求富有弹性；当 |PED| < 1 时，需求缺乏弹性。决定因素包括替代品的可得性、必需品与奢侈品、支出占收入比例以及时间。需求的收入弹性 (YED) = 需求量变化百分比 ÷ 收入变化百分比，对区分正常商品（YED > 0）和低档商品（YED < 0）至关重要。需求的交叉价格弹性 (XED) = 商品A需求量变化百分比 ÷ 商品B价格变化百分比；替代品为正，互补品为负。供给的价格弹性 (PES) = 供给量变化百分比 ÷ 价格变化百分比，取决于闲置产能、库存水平和时期长短。
| Term (术语) | Key insight (核心要点) |
|---|---|
| Perfectly inelastic demand | PED = 0, vertical demand curve / 需求曲线垂直 |
| Unit elastic demand | PED = -1, total revenue unchanged with price change / 价格变化时总收入不变 |
| Luxury good | YED > 1 / 需求收入弹性大于1 |
| Short-run vs. long-run PES | Supply is more elastic in the long run / 长期供给弹性更大 |
4. Producer Behaviour and Costs | 生产者行为与成本
In the short run, at least one factor of production is fixed; in the long run, all are variable. Total product rises, but marginal product eventually falls due to the law of diminishing returns. Fixed costs do not vary with output (e.g., rent), while variable costs change with output. Average total cost (ATC) falls then rises, creating a U-shaped curve. The minimum efficient scale is the lowest output at which long-run average costs are minimised. Economies of scale reduce long-run average costs as output expands; diseconomies of scale raise them. Total revenue = price × quantity. Normal profit is the minimum reward to keep resources in their current use; supernormal profit is any profit above normal.
在短期内，至少有一种生产要素是固定的；长期内所有要素均可变。总产量会增加，但边际产量最终会因边际报酬递减规律而下降。固定成本不随产量变化（如租金），而可变成本随产量变化。平均总成本先降后升，形成U形曲线。最小有效规模是使长期平均成本最小化的最低产出水平。规模经济随着产量扩大而降低长期平均成本；规模不经济则使其上升。总收入 = 价格 × 数量。正常利润是使资源保留在当前用途的最低报酬；超常利润是超出正常利润的任何利润。
- Marginal cost (MC) – the cost of producing one additional unit. / 边际成本 – 多生产一单位产品所增加的成本。
- Productive efficiency – producing at the lowest point on the ATC curve. / 生产效率 – 在平均总成本曲线最低点进行生产。
- Allocative efficiency – price equals marginal cost (P = MC). / 配置效率 – 价格等于边际成本。
- Barriers to entry – obstacles that prevent new firms from entering a market. / 进入壁垒 – 阻止新企业进入市场的障碍。
5. Market Structures | 市场结构
Market structures range from perfect competition to pure monopoly. Perfect competition features many firms, identical products, no barriers, and perfect knowledge; firms are price takers earning only normal profit in the long run. Monopolistic competition has many firms selling differentiated products; some price-setting power exists but new entry erodes supernormal profit. Oligopoly is characterised by a few interdependent firms, high concentration ratios, and potential collusion. The kinked demand curve model explains price rigidity. Monopoly is a single seller with high barriers; it can earn long-run supernormal profit at the expense of allocative efficiency. Contestable markets emphasise the threat of entry – even a monopoly may behave competitively if sunk costs are low.
市场结构从完全竞争到完全垄断不等。完全竞争拥有众多企业、同质产品、无进入壁垒和完全信息；企业是价格接受者，长期只能获得正常利润。垄断竞争有许多销售差异化产品的企业；具有一定的定价能力，但新进入者会侵蚀超常利润。寡头垄断的特征是少数相互依存的企业、高集中度以及可能存在的合谋。弯折的需求曲线模型解释了价格刚性。垄断是存在单一卖方且进入壁垒高的市场；它可以长期赚取超常利润，但牺牲了配置效率。可竞争市场强调进入威胁——如果沉没成本低，即使垄断者也可能采取竞争行为。
- Price discrimination – charging different prices to different consumers for the same product, without cost justification. / 价格歧视 – 无成本差异理由下，对同一产品向不同消费者收取不同价格。
- Cartel – a formal agreement among oligopolists to fix prices and output. / 卡特尔 – 寡头企业间固定价格和产量的正式协议。
- Game theory (Prisoner's dilemma) – explains why collusion can break down. / 博弈论（囚徒困境） – 解释合谋为何可能瓦解。
- Natural monopoly – a single firm can supply the entire market at lower cost due to economies of scale. / 自然垄断 – 因规模经济，单一企业能以更低成本供应整个市场。
6. Market Failure and Externalities | 市场失灵与外部性
Market failure occurs when the free market does not allocate resources efficiently, leading to a net social welfare loss. Externalities are third-party spillover effects not reflected in prices. Negative production externalities (e.g., pollution) cause overproduction because MSC > MPC. Positive consumption externalities (e.g., education) cause underconsumption because MSB > MPB. Public goods are non-excludable and non-rival; the free rider problem leads to underprovision. Merit goods (e.g., healthcare) are underprovided and demerit goods (e.g., tobacco) are overconsumed due to information failure. Information asymmetry creates adverse selection and moral hazard. Imperfect market knowledge and factor immobility also cause market failure.
市场失灵指自由市场未能有效配置资源，导致净社会福利损失。外部性是未反映在价格中的第三方溢出效应。负生产外部性（如污染）因边际社会成本大于边际私人成本而导致过度生产。正消费外部性（如教育）因边际社会收益大于边际私人收益而导致消费不足。公共物品具有非排他性和非竞争性；搭便车问题导致供给不足。有益品（如医疗保健）供给不足，而有害品（如烟草）因信息失灵而过量消费。信息不对称造成逆向选择和道德风险。不完全市场信息和要素不流动性也会导致市场失灵。
- Social optimum – MSB = MSC. / 社会最优 – 边际社会收益等于边际社会成本。
- Tradable pollution permits – cap total emissions and allow firms to trade permits. / 可交易污染许可证 – 设定排放总量上限，允许企业交易许可。
- Pigouvian tax – a tax equal to the marginal external cost. / 庇古税 – 等于边际外部成本的税收。
- Government failure – when intervention worsens resource allocation. / 政府失灵 – 干预导致资源配置恶化。
7. Macroeconomic Performance and Indicators | 宏观经济表现与指标
Macroeconomics examines the economy as a whole. The key government objectives are sustainable economic growth, low and stable inflation, low unemployment, and a satisfactory balance of payments. GDP measures the total value of output; real GDP strips out inflation. CPI and RPI track changes in the general price level. The claimant count and ILO labour force survey are measures of unemployment. The current account records trade in goods, services, income flows, and transfers. Index numbers simplify complex changes over time. Potential conflicts among objectives create policy trade-offs, often illustrated by the Phillips curve (inverse relationship between inflation and unemployment in the short run).
宏观经济学研究整体经济。关键政府目标包括可持续的经济增长、低而稳定的通货膨胀、低失业率以及令人满意的国际收支。GDP衡量产出的总价值；实际GDP剔除通胀因素。CPI和RPI追踪总体价格水平变化。申领失业金人数和国际劳工组织劳动力调查是失业的衡量方式。经常账户记录商品、服务、收入和转移支付流动。指数简化复杂的时间变化。目标之间的潜在冲突导致政策权衡，通常以菲利普斯曲线（短期通胀与失业的反向关系）加以说明。
- GDP deflator – broadest measure of domestic price changes. / GDP平减指数 – 衡量国内价格变化的最广义指标。
- Nominal vs. real wages – real wages = nominal wages adjusted for inflation. / 名义工资与实际工资 – 实际工资 = 名义工资经通胀调整。
- Economic cycle – periodic fluctuations in actual GDP around the trend rate (boom, downturn, recession, recovery). / 经济周期 – 实际GDP围绕趋势率的周期性波动（繁荣、下行、衰退、复苏）。
- Sustainable growth – growth that meets present needs without compromising the future. / 可持续增长 – 满足当代需求而不损害未来的增长。
8. Aggregate Demand and Aggregate Supply | 总需求与总供给
Aggregate demand (AD) comprises consumption (C), investment (I), government spending (G), and net exports (X – M). The AD curve slopes downward due to the wealth effect, interest rate effect, and trade effect. The multiplier effect means an initial injection leads to a larger final increase in national income: multiplier = 1 ÷ (1 – MPC) = 1 ÷ (MPS + MPT + MPM). Short-run aggregate supply (SRAS) is upward-sloping because nominal costs are sticky. Long-run aggregate supply (LRAS) is vertical at the full-employment output, determined by the quantity and quality of factors. Supply-side policies shift LRAS to the right by improving productivity and incentives.
总需求 (AD) 包括消费 (C)、投资 (I)、政府支出 (G) 和净出口 (X – M)。总需求曲线向下倾斜源于财富效应、利率效应和贸易效应。乘数效应指一笔初始注入带来最终国民收入的更大增长：乘数 = 1 ÷ (1 – 边际消费倾向) = 1 ÷ (边际储蓄倾向 + 边际税收倾向 + 边际进口倾向)。短期总供给 (SRAS) 因名义成本粘性而向上倾斜。长期总供给 (LRAS) 在充分就业产出水平上垂直，由生产要素的数量和质量决定。供给侧政策通过提高生产率和激励使LRAS右移。
- Marginal propensity to consume (MPC) – the fraction of additional income spent. / 边际消费倾向 – 新增收入中用于消费的比重。
- Accelerator theory – investment depends on the rate of change of national income. / 加速原理 – 投资取决于国民收入的变化率。
- Deflationary (recessionary) gap – equilibrium below full-employment output. / 通缩（衰退）缺口 – 均衡低于充分就业产出。
- Inflationary gap – AD exceeds full-employment output, pulling prices up. / 通胀缺口 – 总需求超过充分就业产出，拉高价格。
9. Fiscal, Monetary and Supply-Side Policies | 财政、货币与供给侧政策
Fiscal policy uses government spending and taxation to influence AD. Discretionary fiscal policy is deliberate; automatic stabilisers (e.g., progressive tax, unemployment benefits) operate without active intervention. A budget deficit occurs when G > T; the national debt is the accumulation of past deficits. Monetary policy involves central bank manipulation of interest rates, money supply, and credit conditions to achieve price stability. Quantitative easing (QE) is an unconventional tool. Supply-side policies aim to improve the productive capacity and efficiency of the economy: deregulation, tax reform, education and training, and infrastructure investment. Effective supply-side policies shift LRAS rightward, enabling non-inflationary growth.
财政政策运用政府支出和税收影响总需求。相机抉择的财政政策是有意为之；自动稳定器（如累进税、失业救济金）无需主动干预即可运行。预算赤字出现在政府支出大于税收时；国债是历年赤字的累积。货币政策涉及中央银行对利率、货币供应和信贷条件的操控，以实现价格稳定。量化宽松 (QE) 是非常规工具。供给侧政策旨在提升经济的生产能力和效率：放松管制、税制改革、教育培训及基础设施投资。有效的供给侧政策使LRAS右移，实现无通胀增长。
- Crowding out – increased government borrowing raises interest rates, reducing private investment. / 挤出效应 – 政府增加借款推高利率，减少私人投资。
- Laffer curve – suggests high tax rates may reduce revenue by discouraging work and investment. / 拉弗曲线 – 高税率可能因抑制工作和投资而减少税收。
- Transmission mechanism – how monetary policy decisions affect real GDP and inflation through various channels. / 传导机制 – 货币政策决策如何通过各种渠道影响实际GDP和通胀。
- Hysteresis – a prolonged recession can permanently damage the supply side of the economy. / 迟滞效应 – 长期衰退可能对经济供给侧造成永久性损害。
10. Inflation, Deflation and Unemployment | 通货膨胀、通货紧缩与失业
Inflation is a sustained rise in the general price level. Demand-pull inflation occurs when AD exceeds productive capacity; cost-push inflation arises from rising costs (wages, raw materials, indirect taxes). Deflation is a persistent fall in prices, often more dangerous because it increases the real debt burden and can cause a deflationary spiral. Disinflation is a slowdown in the inflation rate. Unemployment types include cyclical (demand-deficient), structural, frictional, and seasonal. The NAIRU (non-accelerating inflation rate of unemployment) is the unemployment rate consistent with stable inflation. Policymakers face a persistent trade-off between unemployment and inflation in the short run.
通货膨胀是总体价格水平的持续上升。需求拉动型通胀发生在总需求超出生产能力时；成本推动型通胀源于成本上升（工资、原材料、间接税）。通货紧缩是价格的持续下降，通常更为危险，因为它增加实际债务负担并可能引发通缩螺旋。反通货膨胀是指通胀率放缓。失业类型包括周期性（需求不足型）、结构性、摩擦性和季节性失业。NAIRU（不加速通胀的失业率）是与稳定通胀相一致的失业率。政策制定者在短期面临通胀与失业之间的持续权衡。
- Stagflation – simultaneous high inflation and high unemployment. / 滞胀 – 高通胀与高失业并存。
- Real wage unemployment – wages above equilibrium, leading to excess supply of labour. / 实际工资失业 – 工资高于均衡水平，导致劳动供给过剩。
- Phillips curve breakdown – in the long run, no trade-off; LRPC is vertical at the NAIRU. / 菲利普斯曲线失效 – 长期无权衡；长期菲利普斯曲线在NAIRU处垂直。
11. International Trade and Globalisation | 国际贸易与全球化
International trade is driven by comparative advantage (lower opportunity cost) and absolute advantage (higher productivity). Free trade increases global allocative efficiency, consumer choice, and output, but may create structural unemployment and trade imbalances. Protectionism includes tariffs, quotas, subsidies to domestic producers, and non-tariff barriers. Globalisation refers to the increasing integration of economies in terms of trade, capital flows, labour movement, and technology. Terms of trade measure the ratio of export prices to import prices; a deterioration means a country must sell more exports to buy the same volume of imports. Trading blocs (e.g., EU single market, USMCA) foster regional integration through preferential agreements.
国际贸易由比较优势（较低的机会成本）和绝对优势（较高的生产率）驱动。自由贸易提升了全球配置效率、消费者选择和产出，但可能造成结构性失业和贸易失衡。保护主义包括关税、配额、对国内生产者的补贴以及非关税壁垒。全球化指各经济体在贸易、资本流动、劳动迁移和技术方面的日益融合。贸易条件衡量出口价格与进口价格的比率；恶化意味着一国必须出口更多才能购买同等数量的进口品。贸易集团（如欧盟单一市场、美墨加协定）通过优惠协议促进区域一体化。
- Infant industry argument – temporary protection for new domestic industries until they become competitive. / 幼稚产业论 – 暂时保护新兴国内产业直至其具有竞争力。
- Dumping – selling abroad below cost or below domestic price. / 倾销 – 以低于成本或国内价格在国外销售。
- Current account deficit – spending on imports, income outflows, and transfers exceeds receipts. / 经常账户赤字 – 进口、收入和转移支付支出超过收入。
- Marshall-Lerner condition – a depreciation improves the trade balance if the sum of price elasticities of exports and imports > 1. / 马歇尔-勒纳条件 – 若进出口价格弹性之和大于1，货币贬值将改善贸易收支。
12. Exchange Rates, Balance of Payments and Financial Markets | 汇率、国际收支与金融市场
The balance of payments records all transactions between a country and the rest of the world. The current account includes trade in goods and services, primary income (interest, dividends), and secondary income (transfers). The financial account records capital flows (FDI, portfolio investment, banking flows). Exchange rates can float freely, be fixed, or managed. A depreciation makes exports cheaper and imports dearer. Under a fixed exchange rate, a central bank intervenes using reserves; a devaluation is an official downward adjustment. Hot money flows respond to interest rate differentials and can cause exchange rate volatility. Foreign direct investment (FDI) adds to a country's capital stock and can boost productivity.
国际收支记录了一国与世界其他地区的所有交易。经常账户包括商品与服务贸易、初次收入（利息、股息）和二次收入（转移支付）。金融账户记录资本流动（外国直接投资、证券投资、银行资金流动）。汇率可以自由浮动、固定或有管理地浮动。贬值会使出口更便宜、进口更昂贵。在固定汇率制下，中央银行使用储备进行干预；法定贬值是官方下调汇率。热钱流动对利差作出反应，可能导致汇率波动。外国直接投资 (FDI) 增加了国家的资本存量，并能提高生产率。
- J-curve effect – after a depreciation, the trade balance worsens before improving. / J曲线效应 – 贬值后，贸易收支先恶化后改善。
- Purchasing power parity (PPP) – exchange rates should adjust to equalise the price of identical goods in different countries. / 购买力平价 – 汇率应调整以使相同商品在不同国家的价格相等。
- Speculative bubble – asset prices driven above their fundamental value by irrational expectations. / 投机泡沫 – 由非理性预期推动，资产价格超过其基本价值。
Published by TutorHao | Economics Revision Series | aleveler.com
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