📚 Year 12 CCEA Economics: Key Terminology Memorisation Guide | CCEA 12年级经济学词汇术语速记指南
Mastering terminology is the first step towards a confident performance in CCEA AS Economics. This guide pairs precise definitions with creative memory hooks for the essential terms covered in Units 1 and 2, helping you recall them quickly under exam pressure.
掌握术语是迈向CCEA AS经济学自信表现的第一步。本指南为单元1和单元2的核心词汇提供了精准定义与创意记忆挂钩，帮助你在考试压力下快速回忆。
1. Scarcity, Choice and Opportunity Cost | 稀缺性、选择与机会成本
Scarcity is the basic economic problem: finite resources cannot satisfy infinite human wants. This forces every economy to make choices. The well-known phrase 'There is no such thing as a free lunch' (TINSTAAFL) sums up scarcity — everything has a cost.
稀缺是基本经济问题：有限资源无法满足无限欲望。这迫使每个经济体做出选择。著名谚语“没有免费的午餐”（TINSTAAFL）概括了稀缺——一切都有代价。
Opportunity cost is the value of the next best alternative forgone when a choice is made. A quick mnemonic: "OC = what you give up." nfuse it with accounting cost; opportunity cost includes both explicit and implicit costs.
机会成本是做出选择时所放弃的次优选项的价值。速记口诀：“机会成本 = 你放弃的。”不要将其与会计成本混淆；机会成本既包括显性成本也包括隐性成本。
2. Production Possibility Frontier (PPF) | 生产可能性边界
The PPF is a curve showing the maximum combinations of two goods an economy can produce with full employment of given resources. Points on the curve represent productive efficiency; inside the curve signals underemployment.
生产可能性边界是显示一个经济体在充分利用给定资源时能生产两种商品最大组合的曲线。曲线上的点代表生产性效率；曲线内部意味着就业不足。
The PPF illustrates scarcity, choice, and opportunity cost all at once. When the PPF is concave (bowed outwards), opportunity cost increases as more of one good is produced. A simple memory rhyme: "Curve bowed out — cost goes up without a doubt."
PPF一次性展示了稀缺、选择和机会成本。当PPF呈凹向原点（向外凸出）时，随着一种商品产量增加，机会成本递增。记忆小韵：“曲线向外凸，机会成本往上走。”
An outward shift of the PPF indicates economic growth, usually caused by more resources or better technology.
PPF向外移动表明经济增长，通常由资源增加或技术进步引起。
3. Demand, Supply and Market Equilibrium | 需求、供给与市场均衡
The law of demand states that, ceteris paribus, as price falls, quantity demanded rises. So the demand curve slopes downwards. The law of supply says quantity supplied rises when price rises, giving an upward-sloping supply curve. Remember them as: "Demand down, Supply up."
需求定律指出，在其他条件不变下，价格下降则需求量上升，因此需求曲线向下倾斜。供给定律指出价格上升则供给量上升，供给曲线向上倾斜。记忆：“需求向下，供给向上。”
ium price, there is no tendency for change; the market clears. A price above equilibrium creates a surplus; a price below causes a shortage.
市场均衡出现在需求等于供给之处（D = S）。在均衡价格下，没有变化趋势，市场出清。高于均衡的价格造成过剩；低于均衡的价格造成短缺。
4. Elasticity – PED, YED, XED, PES | 弹性四兄弟
Price elasticity of demand (PED) measures how responsive quantity demanded is to a change in price. Formula:
需求价格弹性（PED）衡量需求量对价格变化的反应程度。公式：
PED = %ΔQd / %ΔP
If PED > 1, demand is elastic (luxuries); if PED < 1, it is inelastic (necessities). A memory trick: Elastic = Easy to change quantity; INelastic = INsensitive. Revenue rule: price × quantity moves with the dominant effect.
若PED > 1，需求富有弹性（奢侈品）；若PED < 1，缺乏弹性（必需品）。记忆技巧：Elastic = 容易改变量；INelastic = 不敏感。收益规则：价格与数量乘积随主导效应变动。
Income elasticity of demand (YED) = %ΔQd / %ΔY. Normal goods have YED > 0; inferior goods have YED < 0. Cross elasticity (XED) = %ΔQd of good A / %ΔP of good B. Positive XED means substitutes, negative means complements. Price elasticity of supply (PES) = %ΔQs / %ΔP. Key factors: time period and spare capacity.
需求收入弹性（YED）= %ΔQd / %ΔY。正常品的YED > 0；低档品YED < 0。交叉弹性（XED）= A品需求量变化% / B品价格变化%。正值代表替代品，负值代表互补品。供给价格弹性（PES）= %ΔQs / %ΔP。关键因素：时间长度与闲置产能。
5. Consumer and Producer Surplus | 消费者与生产者剩余
Consumer surplus is the difference between the maximum price consumers are willing to pay and the market price they actually pay. It is the area below the demand curve and above the price line — a visual way to remember: "The joy of a bargain."
消费者剩余是消费者愿意支付的最高价格与实际支付的市场价格之差。它是需求曲线下方、价格线上方的面积——视觉记忆：“讨价还价的喜悦”。
Producer surplus is the difference between the market price and the minimum price firms would accept to supply. It is the area above the supply curve and below the price line. Together they measure the net welfare gain from market transactions.
生产者剩余是市场价格与厂商愿意接受的最低供给价格之差。它是供给曲线上方、价格线下方的面积。二者共同衡量市场交易带来的净福利收益。
6. Market Failure and Externalities | 市场失灵与外部性
Market failure occurs when the free market fails to allocate resources efficiently. The main causes include externalities, public goods, information gaps, and monopoly power. For CCEA, remember the acronym EPIM: Externalities, Public goods, Information failure, Market power.
当自由市场未能有效配置资源时，就发生市场失灵。主要原因包括外部性、公共物品、信息不对称和垄断势力。CCEA考试中用缩写EPIM记忆：外部性、公共物品、信息失灵、市场势力。
Externality is a cost or benefit imposed on a third party not directly involved in the transaction. A negative externality (e.g. pollution) means MSC > MPC, causing over-consumption. A positive externality (e.g. vaccination) means MSB > MPB, leading to under-consumption. Use the phrase: "Externalities = spillovers, the market's blind spot."
外部性是强加于未直接参与交易的第三方的成本或收益。负外部性（如污染）意味着边际社会成本大于边际私人成本，导致过度消费。正外部性（如疫苗接种）意味着边际社会收益大于边际私人收益，导致消费不足。用一句话记：“外部性=溢出效应，市场的盲点。”
- Negative externality: MPC < MSC, over-consumption.
- Positive externality: MPB < MSB, under-consumption.
- 负外部性：边际私人成本小于边际社会成本，过度消费。
- 正外部性：边际私人收益小于边际社会收益，消费不足。
7. Public Goods and Information Gaps | 公共物品与信息不对称
Public goods have two characteristics: non-rivalry (my consumption does not reduce yours) and non-excludability (you cannot stop someone from using them). This leads to the free-rider problem and under-provision by the market. Think of a lighthouse or street lighting.
公共物品具有两个特征：非竞争性（我的消费不减少你的消费）和非排他性（不能阻止他人使用）。这导致搭便车问题和市场供给不足。联想到灯塔或路灯。
Information gaps occur when buyers or sellers lack full knowledge. Adverse selection happens before a transaction (e.g. used car 'lemons'), while moral hazard when one party takes extra risks because they are protected (e.g. insurance). Memory aid: "Hidden info before = adverse selection; hidden action after = moral hazard."
信息不对称发生在买方或卖方缺乏充分信息时。逆向选择发生在交易之前（如二手车“柠檬市场”），而道德风险发生在交易之后，一方因为受到保护而冒更大风险（如保险）。记忆辅助：“事前隐藏信息=逆向选择；事后隐藏行动=道德风险。”
8. Government Intervention | 政府干预措施
Governments use various tools to correct market failures. The main interventions include indirect taxes (to internalise negative externalities), subsidies (to encourage positive externalities), maximum/minimum price controls, regulation, and state provision.
政府运用多种工具纠正市场失灵。主要干预措施包括间接税（内化负外部性）、补贴（鼓励正外部性）、最高/最低价格管制、规制和国家提供。
Remember how taxes and subsidies shift supply. An indirect tax shifts the supply curve left (less supply at each price), while a subsidy shifts it right. A simple rule: "Tax left, subsidy right."
记住税收和补贴如何移动供给。间接税使供给曲线向左移动（每个价格下供给减少），补贴使其向右移动。简单规则：“税收向左，补贴向右。”
A maximum price (ceiling) set below equilibrium creates a shortage; a minimum price (floor) above equilibrium leads to a surplus. Both can cause inefficiency if not well designed.
低于均衡的最高限价造成短缺；高于均衡的最低限价造成过剩。若设计不当，两者都可能导致无效率。
9. Macroeconomic Objectives & Indicators | 宏观经济目标与指标
The four main macroeconomic objectives are low inflation, economic growth, low unemployment, and a satisfactory balance of payments. To memorise them quickly, use the acronym BIG E: Balance of payments, Inflation, Growth, Employment.
四大宏观经济目标是低通胀、经济增长、低失业和合意的国际收支平衡。快速记忆用缩写BIG E：国际收支、通胀、增长、就业。
Key indicators include GDP (Gross Domestic Product), the CPI (Consumer Price Index) for inflation, the unemployment rate, and the current account balance. Remember: real GDP strips out inflation, while nominal GDP does not.
关键指标包括GDP（国内生产总值）、衡量通胀的CPI（消费者价格指数）、失业率以及经常账户余额。记住：实际GDP剔除了通胀因素，而名义GDP没有。
10. Aggregate Demand and Aggregate Supply | 总需求与总供给
Aggregate demand (AD) nomy at a given price level. Its components are: AD = C + I + G + (X - M). An easy phrase: "CIG X-M" (Consumption, Investment, Government spending, net eXports).
总需求（AD）是一个经济体在给定价格水平下对商品和服务的总支出。其构成是：AD = C + I + G + (X - M)。简单口诀：“CIG X-M”（消费、投资、政府支出、净出口）。
The AD curve slopes downward due to the wealth effect, interest rate effect, and trade effect. Aggregate supply (AS) in the short run slopes upward; in the long run (LRAS) it is vertical at the full-employment output. Supply-side shocks shift AS.
由于财富效应、利率效应和贸易效应，AD曲线向下倾斜。总供给（AS）在短期向上倾斜；长期总供给（LRAS）在充分就业产出水平上呈垂直线。供给侧冲击会使AS移动。
11. Fiscal and Monetary Policy | 财政与货币政策
Fiscal policy sts AD; contractionary policy does the opposite. The budget balance = T - G; a negative value indicates a deficit.
财政政策涉及政府调整支出和税收收入以影响总需求。扩张性财政政策（增加G、减少T）刺激AD；紧缩性政策则相反。预算平衡 = T - G；负值表示赤字。
Monetary policy uses interest rates and the money supply to manage AD, typically operated by the central bank. A cut in interest rates makes borrowing cheaper, encouraging C and I, thus shifting AD right. Remember: "Rate down, AD up."
货币政策通过利率和货币供给来管理AD，通常由中央银行操作。降低利率使借贷更便宜，鼓励消费和投资，从而使AD右移。记住：“利率下调，AD上升。”
12. International Trade and Exchange Rates | 国际贸易与汇率
The principle of comparative advantage explains why countries trade: a country should specialise in producing goods where it has the lowest opportunity cost. Trade allows both nations to consume beyond their PPF.
比较优势原理解释了为何国家间应进行贸易：一国应专业化生产机会成本最低的商品。贸易使两国都能在PPF之外消费。
Exchange rate movements affect trade flows. A depreciation makes exports cheaper and imports dearer, improving net exports (X-M) and shifting AD right, though the J-curve effect may delay the improvement. Use the mnemonic "Strong Pound Imports Cheaper Exports Dearer" (SPICED) to recall that an appreciation makes imports cheaper and exports more expensive.
汇率变动影响贸易流动。贬值使出口更便宜、进口更昂贵，改善净出口（X-M）并使AD右移，尽管J曲线效应可能延迟改善。用助记语“SPICED”（强英镑进口便宜出口贵）记住升值使进口更便宜、出口更昂贵。
Published by TutorHao | Economics Revision Series | aleveler.com
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