📚 Case Study Mastery: Year 10 WJEC Economics Practical Exercises | 案例分析实战演练：WJEC 十年级经济
In Year 10 WJEC Economics, case studies are not just stories to read; they are puzzles to solve. This article equips you with a systematic approach to decoding real-world scenarios, extracting economic data, and applying theoretical concepts such as demand, supply, elasticity, and government intervention. Through hands-on exercises and model answers, you will learn to move from simple description to high-level evaluation, boosting your confidence for both in-class tests and final assessments.
在WJEC十年级经济课程中，案例分析不仅是阅读材料，更是需要破解的谜题。本文为你提供一套系统的方法，帮助你解读真实情景、提取经济数据，并运用供需、弹性、政府干预等理论概念。通过实践练习和参考答案，你将学会从简单描述进阶到高层次的评估，从而增强应对课堂测验和最终考试的信心。
1. Understanding Case Study Structure | 理解案例分析的结构
WJEC case studies typically open with a short narrative about a market, a firm, or a policy. This introduction is followed by data, charts, or extracts containing economic indicators. Before you read the questions, scan the text for contextual clues: Which product is discussed? What time period is involved? Are we examining a local, national, or global market? Identifying these structural elements saves time and directs your focus.
WJEC的案例分析通常以关于某个市场、企业或政策的简短叙述开头，随后提供数据、图表或包含经济指标的摘录。在阅读问题之前，先扫读文本寻找上下文线索：讨论的是哪种产品？涉及哪个时间段？研究的是本地、全国还是全球市场？识别这些结构性要素可以节省时间，并引导你的关注点。
A useful strategy is to highlight the 'Who, What, Where, and Why' in the opening paragraph. For instance, 'The UK government plans to raise the tax on sugary drinks from 2025' immediately tells you that the case study will explore an indirect tax, its impact on producers and consumers, and likely some health-related externalities. Train yourself to spot these signals.
一个有用的策略是，在开头段落中划出“谁、什么、哪里、为什么”。例如，“英国政府计划从2025年起提高含糖饮料税”这句话立即告诉你，这个案例将探讨一种间接税及其对生产者和消费者的影响，很可能会涉及与健康相关的外部性。训练自己发现这些信号。
Finally, note how marks are distributed among questions. A 2-mark question requires a precise definition or a single calculation. An 8-mark question demands analysis of cause and effect, supported by data and concluding with a well-justified evaluation. Matching your response length to the mark allocation is essential.
最后，注意问题之间的分值分配。一道2分题要求给出准确定义或单一计算。一道8分题则要求分析因果，并用数据支撑，最后给出有充分理由的评估。将回答的篇幅与分值相匹配至关重要。
2. Identifying Key Economic Concepts | 识别关键经济概念
Every case study is built around a handful of core WJEC concepts. Begin by asking: Is the case about price changes, shifts in demand or supply, market failure, or government action? Create a mental checklist: scarcity, opportunity cost, producers, consumers, the price mechanism, PED/PES, externalities, taxation, subsidies, or regulation.
每个案例都围绕WJEC的几个核心概念展开。开始时先问自己：这个案例讨论的是价格变动、供需移动、市场失灵还是政府行为？建立一个心理检查清单：稀缺性、机会成本、生产者、消费者、价格机制、需求价格弹性/供给价格弹性、外部性、税收、补贴或监管。
For example, a case study about a drought affecting wheat harvests immediately points to a leftward shift of the supply curve. This triggers a higher equilibrium price and lower quantity. From there you can link to the price elasticity of demand for bread (a necessity) to explain why total revenue for farmers might actually rise despite a smaller crop. Recognising these link chains turns a simple description into an analytical answer.
例如，一个关于干旱影响小麦收成的案例，立刻指向供给曲线向左移动。这会引发均衡价格上升和数量下降。由此你可以联系面包（一种必需品）的需求价格弹性，来解释为什么尽管收成减少，农民的总收入实际上可能增加。识别这些链条式联系，可以把简单的描述变成分析性答案。
Be prepared for cases that blend concepts. A story about a new minimum wage for delivery drivers might combine labour market analysis with the impact on firms' costs and the potential for substituting capital (technology) for labour. Always underline the concept words in the questions to stay on track.
要做好准备应对结合多个概念的案例。一个关于为送货司机设定新的最低工资的故事，可能结合了劳动力市场分析、对企业成本的影响，以及用资本（技术）替代劳动力的可能性。务必在题干中划出概念词，确保不偏离方向。
3. Extracting Data and Trends | 提取数据与趋势
data provided, not just describe it. When a table shows that the price of coffee rose from $2.50 to $ nd between 2022 and 2024, you must calculate the percentage change: (0.70/2.50) × 100 = 28%. Then interpret what a 28% price increase implies for consumer behaviour, provided you know the PED for coffee.
WJEC阅卷考官期待你使用所提供的数据，而不仅仅是描述它。当一个表格显示咖啡价格从2022年的每磅2.50美元上涨到2024年的3.20美元时，你必须计算百分比变化：(0.70/2.50) × 100 = 28%。然后解释28%的价格上涨对消费者行为意味着什么，前提是你了解咖啡的需求价格弹性。
Trends are often hidden in narratives. You might read, 'Sales of electric vehicles (EVs) have doubled every two years since 2018.' That signals an exponential growth trend. From an economics perspective, this suggests that demand is rising rapidly, likely due to rising incomes, changing preferences, or government subsidies. If you also see a fall in battery costs, you can weave in supply-side improvements. Always convert raw narrative into economic indicators: growth rate, market share, revenue change.
趋势往往隐藏在叙述中。你可能会读到，“自2018年以来，电动汽车（EVs）的销量每两年翻一番。”这标志着指数级增长趋势。从经济学角度看，这表明需求正在快速上升，很可能源于收入增加、偏好变化或政府补贴。如果你还看到电池成本下降，则可以将供给侧改善结合起来分析。始终将原始叙述转化为经济指标：增长率、市场份额、收入变化。
Use graphs wisely. If a case study includes a supply and demand diagram, do not simply redraw it. Instead, explain the movement from equilibrium E1 to E2: 'Due to a successful advertising campaign, the demand curve shifted right, raising both price and quantity. This is shown by the new intersection point.' Labelling diagrams accurately and linking them to the text will earn high marks.
明智地使用图表。如果案例分析中包含供需图，不要只是重画一遍。相反，要解释从均衡点E1到E2的变动：“由于广告推广成功，需求曲线向右移动，价格和数量都上升了。这一点体现在新的交点处。”准确标注图表并将其与文本关联，将获得高分。
4. Applying Demand and Supply Analysis | 运用供需分析
The demand and supply model is your primary toolkit. When a case study mentions a factor that influences buyers, such as changing tastes or a rise in income, you should immediately shift the demand curve. When production costs change because of a new tax or a cheaper raw material, shift the supply curve.
供需模型是你的首要工具。当案例中提到影响买家的因素时，比如口味变化或收入增加，你应该立刻移动需求曲线。当生产成本因为新税或更便宜的原材料而改变时，移动供给曲线。
Always use the correct terminology: an 'increase in demand' shifts the demand curve right; an 'extension in demand' is a movement along the curve due to a price fall. Confusing these two is a common mistake. Practise by isolating a single event: 'A cold winter increases the demand for natural gas.' First, diagram this as a rightward shift. Then, explain how price rises to ration the limited supply among many competing buyers.
始终使用正确的术语：“需求增加”是需求曲线右移；“需求量增加”是由于价格下降引起的沿着曲线的移动。混淆这两者是一个常见错误。通过分离单个事件来练习：“寒冬增加了对天然气的需求。”首先，用图表将此表示为右移。然后，解释价格如何上升，以在众多竞争买家之间配给有限的供应。
Real-world cases often involve both curves moving. For instance, a technological breakthrough reduces the cost of producing solar panels (supply shifts right), while a government subsidy to households increases their willingness to buy (demand shifts right). The final equilibrium quantity will definitely rise, but the effect on price is ambiguous; it depends on the relative magnitude of the shifts. This ambiguity is a perfect way to demonstrate evaluative thinking.
现实世界案例往往涉及两条曲线同时移动。例如，一项技术突破降低了太阳能电池板的生产成本（供给右移），而政府对家庭的补贴提高了购买意愿（需求右移）。最终的均衡数量一定上升，但对价格的影响是不确定的；它取决于移动的相对幅度。这种不确定性是展示评估性思维的绝佳方式。
5. Calculating and Interpreting Elasticity | 计算与解释弹性
ercentage change in quantity demanded ÷ percentage change in price. Remember, ignore the minus sign when interpreting magnitude; a PED of -1.5 means demand is price elastic.
需求价格弹性（PED）经常出现在WJEC案例分析中。你可能会得到原始数据，并被要求用公式计算PED：PED = 需求量变动的百分比 ÷ 价格变动的百分比。记住，在解释弹性大小时忽略负号；PED为-1.5意味着需求富有弹性。
If a case reveals that a firm increased its product's price by 10% and quantity demanded fell by only 5% ing inelastic demand. This information is gold for evaluating a pricing strategy: the firm' calculations back to business decisions or government tax policies. For example, taxing an inelastic product like cigarettes yields high tax revenue and a smaller reduction in quantity, making it an effective fiscal tool.
如果案例显示，一家公司将其产品提价10%，而需求量仅下降5%，那么PED = -0.5，表明需求缺乏弹性。这一信息对于评估定价策略极为宝贵：公司的总收入将上升。始终将计算结果与商业决策或政府税收政策联系起来。例如，对香烟这类需求缺乏弹性的产品征税，能产生高额税收，同时数量减少较小，使其成为有效的财政工具。
Price elasticity of supply (PES) is also testable. A case might describe farmers switching from wheat to corn easily, implying a high PES for corn. Or a case about vintage wine, which cannot be increased in supply quickly, indicates a very low or zero short-run PES. Highlighting the time period is critical because supply elasticity always changes from the short run to the long run.
供给价格弹性（PES）同样可考。一个案例可能描述农民很容易从小麦转种玉米，这意味着玉米的PES较高。或者，关于陈年葡萄酒的案例，其供给无法迅速增加，表明短期PES非常低甚至为零。强调时间周期至关重要，因为供给弹性从短期到长期总会发生变化。
6. Analysing Market Structures | 分析市场结构
WJEC Year 10 introduces basic market structures: perfect competition, monopoly, and oligopoly. A case study might describe a market with many small firms selling identical strawberries (perfect competition), or a patented pharmaceutical drug sold by one firm (monopoly). Identify the number of firms, the degree of product differentiation, and the ease of entry and exit.
WJEC十年级介绍了基本的市场结构：完全竞争、垄断和寡头垄断。一个案例可能描述一个拥有许多销售同质草莓的小型企业的市场（完全竞争），或者描述一种由独家销售的专利药品（垄断）。识别企业的数量、产品差异化程度，以及进入和退出的难易程度。
When analysing a monopoly case, focus on the ability to set prices above the competitive level, leading to higher producer surplus but also potential consumer exploitation. A common WJEC extract might show an energy firm earning 'supernormal profits' year after year. This immediately signals barriers to entry, such as huge capital costs or legal patents. Your analysis should then explain why this leads to market failure (lack of allocative efficiency) and what government could do (price caps, windfall taxes, or promoting competition).
分析垄断案例时，要重点关注其将价格设定在竞争水平之上的能力，这会导致更高的生产者剩余，但也可能剥削消费者。一个常见的WJEC摘录可能显示，一家能源公司年复一年地赚取“超额利润”。这立即表明存在进入壁垒，例如巨大的资本成本或法律专利。你的分析接着应解释这为何导致市场失灵（缺乏配置效率），以及政府可以做什么（价格上限、暴利税或促进竞争）。
Oligopoly cases are rich with interdependence. A case might say 'Supermarket A cut its petrol price, and within hours Supermarkets B and C did the same.' This is a kinked demand curve in action. Use game theory terms like 'price war' or 'collusion' where appropriate, always linking back to the concentration ratio if given in the data.
寡头垄断案例充满了相互依赖性。一个案例可能说：“超市A降低了汽油价格，几小时内超市B和C也这样做了。”这就是弯折需求曲线在起作用。视情况使用博弈论术语如“价格战”或“合谋”，如果数据中给出了集中率，务必将其关联起来。
7. Evaluating Government Policies | 评估政府政策
Evaluation is the highest-order skill. A case might state 'The government imposed a £1 tax per plastic bag to reduce litter.' A simple analysis explains how the tax shifts the supply curve left, raises price, and cuts quantity. Evaluation goes further: Is demand for plastic bags elastic or inelastic? Will consumers switch to reusable bags? What is the impact on small retailers versus large supermarkets? How does the cost of administering the tax compare to the environmental gain?
评估是最高阶的技能。一个案例可能说：“政府为减少垃圾，对每个塑料袋征收1英镑的税。”简单分析会解释税收如何使供给曲线左移、推高价格并减少数量。评估则更进一步：对塑料袋的需求是富有弹性还是缺乏弹性？消费者会改用可重复使用的袋子吗？对小零售商与大型超市的影响有何不同？税收的征管成本与环境收益相比如何？
Always look for the stakeholders mentioned in the case: consumers, producers, workers, the government, and the environment. A well-rounded evaluation acknowledges that a policy may benefit one group while harming another. For example, a minimum price for alcohol reduces binge drinking (social benefit), but it may increase illegal trade and cut low-income households' disposable income. Using the case data to weigh these trade-offs is what separates top-level students.
始终寻找案例中提到的利益相关者：消费者、生产者、工人、政府和环境。一个全面的评估会承认，一项政策可能有益于某个群体，同时损害另一个群体。例如，酒精的最低限价减少了酗酒行为（社会收益），但可能增加非法贸易，并减少低收入家庭的可支配收入。利用案例数据权衡这些取舍，是顶尖学生与普通学生的区别所在。
Time lags, unintended consequences, and the effectiveness of a policy depend on the specific context. If a case study is set in a country with a large informal economy, raising taxes may simply drive activity further underground. State clearly: 'The success of this intervention hinges on...' and support with evidence from the text.
时间滞后、意外后果和政策有效性取决于具体情境。如果案例设定在一个存在庞大非正规经济的国家，增税可能只会将活动进一步推向地下。明确陈述：“这项干预的成功取决于……”并用文本中的证据加以支撑。
8. Structuring 6-Mark and 8-Mark Answers | 构建6分和8分答案
A 6-mark WJEC question usually requires knowledge, application, and analysis (KAA). Start with a clear definition of the key term, then apply it directly to the case study, and finally analyse the cause-and-effect chain. For instance: 'Define opportunity cost (2 marks). Using the case, explain the opportunity cost for a student choosing to study instead of working (4 marks).' Your answer: 'Opportunity cost is the next best alternative forgone. In the case, Lina works 10 hours a week earning £8 per hour. If she quits to study, her opportunity cost is £80 per week, which represents the lost income she could have earned.'
一道6分的WJEC题目通常要求知识、应用和分析（KAA）。以关键术语的明确定义开头，然后直接应用到案例中，最后分析因果链条。例如：“定义机会成本（2分）。运用案例，解释一名学生选择学习而非工作的机会成本（4分）。”你的答案：“机会成本是所放弃的次优替代选择。在案例中，莉娜每周工作10小时，时薪8英镑。如果她辞职去学习，她的机会成本是每周80英镑，这代表了她本可以赚取的收入损失。”
8-mark questions add evaluation. A classic structure is: Definition (1 mark), Application/Analysis chain (3 marks), Evaluation paragraph with 'However...' or 'It depends on...' (4 marks). When evaluating, never simply list advantages and disadvantages. Instead, weigh them: 'Although the subsidy reduces the price of solar panels for consumers, it is funded by taxpayers. Given that the case shows demand is already rising due to environmental awareness, the subsidy may represent a significant government expense for a relatively small additional gain.'
8分题增加了评估。经典结构为：定义（1分），应用/分析链（3分），以及带有“然而……”或“这取决于……”的评估段落（4分）。评估时，切勿只罗列优缺点，而要进行权衡：“虽然补贴降低了消费者购买太阳能电池板的价格，但它由纳税人出资。鉴于案例显示，由于环保意识，需求已经在上升，这项补贴可能意味着政府巨大开支，而额外收益相对较小。”
Use connectives deliberately: 'This leads to...', 'Consequently...', 'A counter-argument is that...', 'On balance...'. And always, always refer back to the names, figures, and events given in the case study — generic answers score poorly. If the case is about 'FarmFresh Ltd.', use the firm's name in every paragraph.
有意识地使用连接词：“这导致……”“因此……”“一个反对的论点是……”“总而言之……”。并且始终、始终要回溯案例中给出的人名、数据和事件——笼统的答案得分很低。如果案例是关于“新鲜农场有限公司”，每个段落都要使用公司名称。
9. Worked Example: The Coffee Market | 案例详解：咖啡市场
Let's bring everything together with a WJEC-style extract: 'Global coffee bean prices surged 25% in 2023 due to frost in Brazil. At the same time, a new health report linked moderate coffee consumption to longer life expectancy. Cafe Nero, a large coffee chain, increased its average drink price from £2.80 to £3.20 and noticed that sales dipped by only 8%. It also introduced a loyalty card app, reducing waiting times and boosting sales by 15%.'
让我们用一个WJEC风格摘录来汇总所有内容：“2023年，由于巴西霜冻，全球咖啡豆价格飙升25%。与此同时，一份新的健康报告将适度饮用咖啡与更长的预期寿命联系起来。大型连锁咖啡店Cafe Nero将其饮料平均价格从2.80英镑提高到3.20英镑，发现销售额仅下降8%。它还推出了积分卡应用程序，减少了等待时间，并使销售额提升15%。”
razil → supply shock (supply curve left). Health report → right shift in demand. Cafe Nero's 8% sales drop for a 14.3% price increase (from £2.80 to £ = -0.56, inelastic. Loyalty app → improvement in technology/efficiency, shifting the firm's supply curve right or increasing demand further. All are interconnected.
第一步：识别概念。巴西霜冻 → 供给冲击（供给曲线左移）。健康报告 → 需求右移。Cafe Nero价格从2.80英镑涨到3.20英镑，涨幅14.3%，销售额仅降8% → PED = -0.56，缺乏弹性。积分卡应用程序 → 技术/效率改进，推动企业供给曲线右移或使需求进一步增加。所有因素相互关联。
Step 2: Diagram. Draw a global coffee market diagram: supply shifts left, demand shifts right. Equilibrium price rises significantly, quantity could rise or fall depending on magnitudes (but the price is clearly higher). Then, for Cafe Nero, a separate diagram showing that its price increase along an inelastic demand curve led to higher total revenue.
第二步：图表。画一个全球咖啡市场图：供给左移，需求右移。均衡价格大幅上升，数量根据移动幅度可能增加也可能减少（但价格明显上升）。然后，针对Cafe Nero，单独画出图表，显示在非弹性需求曲线上提高价格导致总收入增加。
Step 3: Evaluation. 'Despite the wholesale price spike, Cafe Nero managed to raise its own prices and still increase total revenue due to the inelastic nature of its customers' demand. However, in the long run, consumers may switch to cheaper alternatives or brew coffee at home, especially as the loyalty app data might be used to target discounts, which could erode profit margins. Furthermore, the health report's effect on demand may be temporary. Thus, Cafe Nero's current success relies heavily on continued brand loyalty and short-run consumer habits.'
第三步：评估。“尽管批发价格飙升，Cafe Nero仍设法提高了自身的价格，并且由于顾客需求缺乏弹性，还增加了总收入。然而，从长远来看，消费者可能会转向更便宜的替代品或在家冲泡咖啡，特别是当积分卡应用数据可能被用于提供定向折扣时，这可能会侵蚀利润率。此外，健康报告对需求的影响可能是暂时的。因此，Cafe Nero当前的成功在很大程度上依赖于持续的品牌忠诚度和短期消费者习惯。”
10. Practice Case Study with Model Answers | 案例练习与参考答案
Now it's your turn. Read the following case and then attempt the questions. Answers are provided to check your work.
现在轮到你了。阅读下面这个案例，然后回答问题。提供了参考答案以供核对。
Case Extract: The UK EV Charging Network
案例摘录：英国电动汽车充电网络
'In 2024, the UK had 50,000 public charging points serving 1.2 million electric vehicles. The government announced a £300 million subsidy to install a further 200,000 chargers by 2026. Electricity supply companies reported that wholesale electricity prices had fallen by 10% due to increased wind power capacity. However, the price per charging session for drivers rose from £15 to £18, and usage dipped by only 5%. Local councils have also introduced a £2 per charge levy on public chargers to fund road repairs.'
“2024年，英国拥有5万个公共充电桩，为120万辆电动汽车提供服务。政府宣布拨款3亿英镑补贴，在2026年前再安装20万个充电桩。电力供应公司报告称，由于风电装机容量增加，批发电价下降了10%。然而，司机每次充电的费用从15英镑上涨到18英镑，而使用量仅下降了5%。地方议会还对公共充电桩引入每度2英镑的附加费，用于道路维修。”
Question 1 (6 marks): Using the data, explain the effect of the government subsidy on the market for charging points.
问题1（6分）： 使用数据，解释政府补贴对充电点市场的影响。
Model Answer: A subsidy is a grant from the government to reduce the cost of production or encourage output. In this case, the £300 million subsidy lowers the cost of installing charging points for firms. This shifts the supply curve for charging infrastructure to the right. The quantity supplied of charging points is expected to increase sharply from 50,000 towards a target of 250,000. As a result, more drivers will have access to chargers, reducing range anxiety and potentially encouraging more EV purchases.
参考答案： 补贴是政府为降低生产成本或鼓励产出而提供的拨款。在本案例中，3亿英镑补贴降低了企业安装充电点的成本。这使充电基础设施的供给曲线右移。充电点的供给量预计将从5万个大幅增至25万个的目标。因此，更多司机能够使用充电桩，这将减少里程焦虑，并可能鼓励更多人购买电动汽车。
Question 2 (8 marks): Evaluate the impact of the £2 council levy on the market for public EV charging. Use a diagram and the PED data in your answer.
问题2（8分）： 评估2英镑议会附加费对公共电动汽车充电市场的影响。在回答中使用图表和PED数据。
Model Answer: S2, raising the equilibrium price, for example from P1 to P2, and reducing quantity. Using the case data, the price per session rose from £15 to £18, a 20% increase, while usage fell by 5%. PED = -5% / 20% ant funds for road repairs. However, evaluation suggests that because demand is inelastic, the levy places a disproportionate burden on existing EV drivers who have few short-run alternatives, making it regressive. In the long run, if PES is elastic, the supply curve shift may be even smaller if firms absorb part of the levy, but the case data implies charging firms passed the full cost to consumers. Moreover, the levy works against the government' ates a policy conflict that may require an exemption for low-income users to be equitable.
参考答案： 附加费相当于一种间接税，增加了每次充电服务的成本。这使公共充电的供给曲线从S1左移至S2，提高了均衡价格，例如从P1升至P2，并减少了数量。根据案例数据，每次费用从15英镑涨至18英镑，涨幅20%，而使用量下降5%。PED = -5% / 20% = -0.25，极度缺乏弹性。因此，附加费带来的总收入将很高，因为数量下降很小。议会将为道路维修筹集大量资金。然而，评估表明，由于需求缺乏弹性，附加费对短期替代选择较少的现有电动车司机造成了不成比例的负担，呈现累退性。长期来看，如果PES富有弹性，当企业自行消化部分附加费时，供给曲线的移动可能更小，但案例数据暗示充电企业将全部成本转嫁给了消费者。此外，附加费与政府补贴目标相悖，它提高了电动车使用成本，可能减缓普及速度。总而言之，虽然附加费能筹集稳定收入，但它造成了政策冲突，可能需要对低收入用户实行豁免，才显得公平。
Published by TutorHao | Economics Revision Series | aleveler.com
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