📚 Pre-U OCR Economics: Key Terms Memory Guide | Pre-U OCR经济：词汇术语速记指南
Acing Pre-U OCR Economics demands fluent command of a vast and precise vocabulary. This guide distils the most exam-critical terms into plain English explanations and memory triggers – from pinpointing the opportunity cost to decoding the J‑curve. Each entry pairs a concise English definition with its Chinese equivalent, followed by a mnemonic or application tip to anchor the concept firmly in your revision.
在Pre-U OCR经济学考试中脱颖而出，需要流利掌握大量且精准的术语。本指南将考试中最关键的术语浓缩为通俗易懂的英文解释和记忆触发点——从确定机会成本到解读J曲线。每个词条都将简洁的英文定义与对应的中文释义配对，并辅以助记法或应用提示，帮助你在复习中牢固扎根。
1. Scarcity, Choice & Opportunity Cost | 稀缺性、选择与机会成本
Scarcity: Scarcity is the unbridgeable gap between unlimited wants and finite resources. It is the foundational economic problem that forces every society to decide what, how, and for whom to produce. Memory hook: 'scarce' rhymes with 'sparse' – resources are always sparse relative to desires.
稀缺性：稀缺性是指无限欲望与有限资源之间无法弥合的差距。这是根本的经济问题，迫使每个社会决定生产什么、如何生产以及为谁生产。记忆联想：'scarce' 与 'sparse' (稀少的) 押韵——资源相对于欲望永远稀少。
Opportunity Cost: The opportunity cost of a choice is the value of the next best alternative that must be sacrificed. The classic reminder is 'There Is No Such Thing As A Free Lunch' (TINSTAAFL) – every decision carries an invisible price tag.
机会成本：一项选择的机会成本是必须放弃的次优选项的价值。经典提示是 "天下没有免费的午餐" (TINSTAAFL)——每个决定都带有一个看不见的代价标牌。
Production Possibility Frontier (PPF): A PPF depicts the maximum attainable combinations of two outputs with existing resources and technology. Its bowed‑out shape represents increasing opportunity cost, since resources are not equally suited to all activities. Mnemonic: 'Pushing the Frontier' – you can only produce beyond the curve if the economy grows.
生产可能性边界 (PPF)：PPF描绘了在现有资源和技术下可达到的两种产品的最大组合。它外凸的形状代表了递增的机会成本，因为资源并非同样适合所有生产活动。助记: '推动边界'——只有经济增长才能使产量超越曲线。
2. Demand, Supply & Elasticities | 需求、供给与弹性
Price Elasticity of Demand (PED): PED = %ΔQd ÷ % greater than 1 signals elastic demand: a price cut raises total revenue. A foolproof trick – use the total revenue test: if revenue moves opposite to price, demand is elastic.
需求价格弹性 (PED)：PED = 需求量变动的% ÷ 价格变动的%。大于1意味着富有弹性：降价会增加总收益。一个万无一失的技巧是使用总收益检验法：如果收益变动方向与价格相反，则需求有弹性。
Price Elasticity of Supply (PES) easures how responsive quantity supplied is to a price change. The key determinant is time – pply is highly inelastic (PES≈0), while in the long run it becomes more elastic. Mnemonic: 'Producers need time to stretch output'.
供给价格弹性 (PES)：PES衡量供给量对价格变化的反应程度。关键决定因素是时间——在瞬时阶段供给高度无弹性 (PES≈0)，而在长期则变得更有弹性。助记: '生产者需要时间伸展产出'。
Cross Elasticity of Demand (XED): XED = %ΔQd of good A ÷ % tutes (Coke vs Pepsi); negative XED marks complements (printers and ink). Memory shortcut: 'Complement = Co‑negative'.
需求交叉弹性 (XED)：XED = A商品需求量变动的% ÷ B商品价格变动的%。正值XED表示替代品(可口可乐与百事可乐)；负值XED表示互补品(打印机和墨水)。记忆捷径: 'Complement = Co‑negative' (互补即同负)。
3. Market Failure & Public Goods | 市场失灵与公共品
Negative Externality: A negative externality occurs when a third party bears costs not reflected in the market price, e.g. pollution from a factory. Society's marginal cost exceeds the private marginal cost, causing over‑production. Memory fix: 'Third‑party spillover costs – fix with a tax that internalises the external'.
负外部性：当第三方承担了市场价格未能反映的成本时，就出现负外部性，例如工厂污染。社会边际成本超过私人边际成本，导致过量生产。记忆修正: '第三方溢出成本——用税收将外部性内部化'。
Public Goods: Public goods are non‑rival (one person's consumption does not reduce availability) and non‑excludable (you cannot stop free riders). National defence and street lighting are classic examples. The twin 'non‑' features cause market failure because private firms cannot charge a price. Memory rhyme: 'Non‑rival, non‑excludable? Government time!'
公共品：公共品具有非竞争性(一人的消费不减少可用性)和非排他性(无法阻止搭便车者)。国防和路灯是典型例子。这对 "非" 特性导致市场失灵，因为私人企业无法收费。记忆谐音: 'Non‑rival, non‑excludable? Government time!'
Information Asymmetry : This arises when buyers and sellers have unequal knowledge, leading to adverse selection or moral hazard. Think of the 'Market for Lemons': used‑ bout vehicle quality than buyers, which can drive good cars out of the market. Quick grab: 'Asymmetry = unfair knowledge'.
信息不对称：当买卖双方知识不对等时会产生信息不对称，导致逆向选择或道德风险。想想 "柠檬市场"：二手车卖家比买家更了解车况，这可能导致好车退出市场。速记: 'Asymmetry = 不公平的信息'。
4. Macroeconomic Aims & Indicators | 宏观经济目标与指标
Inflation: A sustained increase in the general price level, commonly measured by the Consumer Price Index (CPI). Demand‑pull inflation is driven by excessive aggregate demand; cost‑push inflation by rising input costs. Visual cue: too much money chasing too few goods (demand‑pull).
通货膨胀：一般物价水平的持续上升，通常用消费者物价指数(CPI)衡量。需求拉动型通胀由过度总需求驱动；成本推动型通胀由投入成本上升驱动。视觉提示: 过多货币追逐过少商品(需求拉动)。
Unemployment: Pre‑ l rate of unemployment (NRU) exists even when the economy is at full capacity. Memory aid: 'Frictional = Finding, Structural = Skills shift, Cyclical = Cold economy'.
失业：Pre‑U 要求分类：摩擦性(换工作期间)、结构性(技能不匹配)和周期性(需求疲软)。即使在产能充分利用时也存在自然失业率(NRU)。记忆助益: '摩擦性 = 找工作，结构性 = 技能变迁，周期性 = 经济冷'。
Economic Growth , driven by an increase in the quantity or quality of factors of production. Simple split: 'Actual = using slack; Potential = expanding capacity'.
经济增长：实际增长是实际GDP的提高，即在PPF内部向边界移动。潜在增长是PPF本身向外移动，由生产要素数量或质量的提高驱动。简单区分: '实际 = 利用闲置；潜在 = 扩充产能'。
5. Aggregate Demand & Aggregate Supply | 总需求与总供给
Aggregate Demand (AD) four components trigger curve shifts: consumer confidence moves C, interest rates move I, fiscal policy shifts G, and exchange rates alter net exports. Memory phrase: 'CIG‑X‑M drives the economy'.
总需求 (AD)：AD = C + I + G + (X - M)。这四个组成部分引发曲线移动：消费者信心影响C，利率影响I，财政政策移动G，汇率改变净出口。记忆短语: 'CIG‑X‑M 驱动经济'。
Long‑Run Aggregate Supply (LRAS): Classical LRAS is vertical at the full‑employment output, assuming perfect wage‑ n LRAS is horizontal at low output (spare capacity) and eventually vertical. Contrast fix: 'Classical = vertical vision; Keynesian = bent path'.
长期总供给 (LRAS)：古典LRAS在充分就业产出处垂直，假设工资价格完全弹性。凯恩斯LRAS在低产出时水平(存在闲置产能)，最终走向垂直。对比记忆: '古典 = 垂直视野；凯恩斯 = 弯曲路径'。
The Multiplier Effect crease in national income. The formula is k = 1/(1 - MPC) = 1/(MPS + MPT + MPM). Mnemonic: 'One pound spent, many pounds created – the wage‑spend‑wage ripple'.
乘数效应：一笔最初支出注入导致国民收入更大倍数的最终增加。公式为 k = 1/(1 - MPC) = 1/(MPS + MPT + MPM)。助记: '一英镑支出，多英镑产出——工资‑消费‑工资的连锁反应'。
6. Fiscal & Monetary Policy | 财政与货币政策
Fiscal Policy: The government' nsionary policy (cut taxes, raise G) boosts GDP but may widen budget deficit. Memory note: 'Fiscal = Treasury tools, T and G'.
财政政策：政府利用税收(T)和政府支出(G)影响总需求。扩张性政策(减税、增支)提高GDP，但可能扩大预算赤字。记忆要点: '财政 = 财政部工具，T与G'。
Monetary Policy ht money (higher rates) cools the economy; easy money (lower rates) heats it up. Mnemonic: 'Monetary = Money levers'.
货币政策：中央银行操纵利率、货币供给或量化宽松(QE)来引导总需求和通胀。紧缩货币(加息)使经济降温；宽松货币(降息)使经济升温。助记: 'Monetary = 货币杠杆'。
Crowding Out it : When expansionary fiscal policy raises government borrowing, it can drive up interest rates and reduce private investment. This weakens the multiplier. 'Crowding out' = 'Government borrowing shoves private investment out of the limelight'.
挤出效应：当扩张性财政政策抬高政府借贷时，会推高利率并减少私人投资，从而削弱乘数。'挤出效应' = '政府借款将私人投资挤出聚光灯'。
7. International Trade & Comparative Advantage | 国际贸易与比较优势
Comparative Advantage: A country has comparative advantage in producing a good if its opportunity cost is lower than that of its trading partner. Trade is mutually beneficial even if one country has absolute advantage in everything. Core mantra: 'Compare opportunity costs, not hours of work'.
比较优势：如果一个国家生产某种商品的机会成本低于其贸易伙伴，则该国具有比较优势。即使一国在所有方面都有绝对优势，贸易仍然互利。核心口诀: '比机会成本，不比工时'。
Terms of Trade: The ratio of export prices to import prices (index). An improvement means a given volume of exports buys more imports. Mnemonic: 'Terms of trade turn in your favour when export prices rise relative to imports'.
贸易条件：出口价格与进口价格的比率(指数)。贸易条件改善意味着一定量出口能购买更多进口。助记: '当出口价格相对于进口价格上涨时，贸易条件转向对你有利'。
Protectionism (Tariffs) welfare loss. The tariff diagram yields government revenue but punishes consumers. Memory: 'Tariff = tax on imported goods, painting a wedge between world and domestic price'.
保护主义 (关税)：关税是对进口商品征收的税，表现为供给曲线上移。它提高国内价格、减少进口，并造成无谓福利损失。关税图解带来政府收入却惩罚消费者。记忆: '关税 = 对进口商品征税，在世界价格与国内价格之间打入一个楔子'。
8. Balance of Payments & Exchange Rates | 国际收支与汇率
Current Account econdary income (transfers). A deficit means the country spends more abroad than it earns. 'Current = real flows of goods, services and income'.
经常账户：国际收支的一部分，记录商品贸易、服务、初次收入(投资收益)和二次收入(转移支付)。赤字意味着该国在国外的支出超过其收入。'经常 = 商品、服务和收入的实体流动'。
Marshall‑Lerner Condition: States that a depreciation of the domestic currency will improve the current account only if the sum of the price elasticities of demand for exports and imports is greater than 1. Formula: |PEDx| + |PEDm| > 1. Memory: 'ML >1 for success – elasticities must sum above unity'.
马歇尔‑勒纳条件：指出本币贬值只有在出口和进口需求价格弹性之和大于1时才能改善经常账户。公式: |PEDx| + |PEDm| > 1。记忆: 'ML 大于1才成功 — 弹性之和必须超过 1'。
J‑Curve Effect: In the short run after a depreciation, the current account worsens because import contracts are sticky, before improving later. The path of the trade balance resembles a 'J' over time. Graphic mnemonic: 'Slump first, then surge – the J‑curve dip'.
J曲线效应：贬值后短期经常账户先恶化，因为进口合同存在黏性，随后才改善。贸易余额随时间呈 "J" 形轨迹。图形助记: '先骤降，后飙升 — J型下探'。
9. Economic Growth & Development | 经济增长与发展
Human Development Index (HDI) years of schooling), and GNI per capita (PPP). It captures development beyond GDP. Recall: 'HDI = Health + Knowledge + Income – three pillars of human wellbeing'.
人类发展指数 (HDI)：一个综合指数，结合预期寿命、教育(平均受教育年限和预期受教育年限)以及人均GNI(购买力平价)。它衡量超越GDP的发展。记忆: 'HDI = 健康 + 知识 + 收入 — 人类福祉的三根支柱'。
Sustainable Development: Development that meets present needs without compromising future generations' ability to meet theirs. It links economic, social, and environmental goals. Key phrase: 'Don't eat your seed corn – pursue growth that can be maintained'.
可持续发展：既满足当代需求，又不损害后代满足其需求的发展。它将经济、社会和环境目标联系起来。关键短语: '不能吃掉种子
Published by TutorHao | Pre-U 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