📚 Case Study Practice in Year 9 CAIE Economics | Year 9 CAIE 经济：案例分析实战演练
Case studies are an essential part of CAIE Economics. They bridge the gap between textbook theory and real-world application. In this article, we will walk through a hands-on case study step by step, showing you exactly how to analyse an economic situation, use key concepts, and structure your answers for top marks. By the end, you will feel confident tackling any case study question in your Year 9 assessments.
案例分析是 CAIE 经济学的重要组成部分。它们弥合了教科书理论与现实应用之间的鸿沟。在这篇文章中，我们将逐步进行一个亲手实践的案例分析，向你展示如何准确分析一个经济情况、运用关键概念并为获得高分构建你的答案。到最后，你将有信心应对九年级评估中的任何案例分析题。
1. Introduction to Case Studies | 案例分析入门
A case study in economics presents a scenario involving individuals, businesses, or governments making choices when resources are limited. Your job is to apply economic concepts such as scarcity, opportunity cost, and demand and supply to explain what is happening. Year 9 case studies are typically short, focused, and based on everyday situations.
经济学中的案例分析会给出一个涉及个人、企业或政府在资源有限时做出选择的场景。你的任务就是运用稀缺性、机会成本以及需求与供给等经济概念来解释发生了什么。九年级的案例分析通常简短、主题集中，并以日常情景为基础。
Common topics include: why a student chooses between two revision methods, how a coffee shop sets its prices, or what happens when a government taxes sugary drinks. The key is always to link the facts to theory.
常见的主题包括：为什么一名学生要在两种复习方法之间做出选择、一家咖啡店如何设定价格，或当政府对含糖饮料征税时会发生什么。关键始终是将事实与理论联系起来。
2. The Core Economic Problem | 核心经济问题
Every case study starts with the basic economic problem: scarce resources and unlimited wants. As a result, economic agents must make choices, and every choice carries an opportunity cost. When reading a case, always identify what is scarce, who is making the choice, and what has been given up.
每个案例研究都始于基本的经济问题：有限的资源和无限的欲望。因此，经济主体必须做出选择，而每个选择都伴有机会成本。阅读案例时，一定要识别出什么是稀缺的、谁在做选择，以及放弃了什么。
For example, if a student has two hours of free time, the scarce resource is time. Choosing to study economics means giving up playing video games. This trade-off is the foundation of economic thinking.
例如，如果一名学生有两小时的空闲时间，稀缺资源就是时间。选择学习经济学意味着放弃玩电子游戏。这种权衡是经济思维的基础。
3. Case: The Coffee Shop Decision | 案例：咖啡店决策
Let us work through a real case. Jenny runs a small, independent coffee shop near a busy train station. Recently, she has noticed that the price of coffee beans has increased sharply. She is considering raising the price of a cup of coffee from £3.00 to £3.50. But she worries that customers might go to the new chain cafe that just opened across the street.
让我们来研究一个真实案例。珍妮在繁忙的火车站附近经营着一家小型的独立咖啡店。最近，她注意到咖啡豆的价格大幅上涨。她正考虑将一杯咖啡的价格从 3.00 英镑提高到 3.50 英镑。但她担心顾客可能会到刚在街对面开张的连锁咖啡店去。
Your task is to advise Jenny using economic concepts. We will break this down into smaller parts: identifying scarcity, analysing demand and supply, and evaluating her options.
你的任务是运用经济概念为珍妮提供建议。我们将把它分解成更小的部分：识别稀缺性、分析需求与供给，并评估她的各种选择。
4. Identifying Scarcity and Choice | 识别稀缺性与选择
In Jenny’s situation, the scarce resources are her supply of coffee beans and her customers’ limited income. Jenny must choose how to respond to rising costs. Her customers will also make a choice: continue buying from Jenny or switch to the competitor.
在珍妮的情境中，稀缺资源是她的咖啡豆供应以及她顾客有限的收入。珍妮必须选择如何应对上涨的成本。她的顾客也将做出选择：继续从珍妮这里购买，还是转向竞争对手。
Scarcity forces trade-offs. Jenny cannot keep both high profits and low prices if costs have risen. She needs to decide which goal is more important. This is a classic economic choice.
稀缺性迫使做出权衡。如果成本已经上升，珍妮不可能同时保持高利润和低价格。她需要决定哪个目标更重要。这是一个经典的经济选择。
5. Opportunity Cost in Action | 机会成本实战
Opportunity cost is the next best alternative forgone. If Jenny raises her price, the opportunity cost might be losing some loyal customers. If she keeps the price at £3.00, the opportunity cost is lower profit per cup, which could make it harder to pay her rent or buy better beans.
机会成本是为之放弃的次优选择。如果珍妮提高了价格，机会成本可能是失去一些忠实顾客。如果她把价格保持在 3.00 英镑，机会成本就是每杯咖啡的利润更低，这可能导致她更难以支付房租或购买更好的咖啡豆。
For a customer, choosing a £3.50 coffee at Jenny’s means giving up a £2.80 coffee from the chain — plus the extra 70 pence that could have been spent elsewhere, perhaps on a snack. Opportunity cost helps us understand behaviour.
对于顾客来说，选择珍妮店里 3.50 英镑的咖啡意味着放弃连锁店里 2.80 英镑的咖啡——外加本可以花在别处的 70 便士，也许是一份点心。机会成本有助于我们理解人们的行为。
6. Demand and Supply in a Local Market | 本地市场中的需求与供给
Now let us apply demand and supply analysis. The demand for Jenny’s coffee depends on factors like taste, price, income, and the price of substitutes, such as the chain cafe’s coffee. The supply of Jenny’s coffee is affected by the cost of production, especially coffee beans.
现在让我们运用需求与供给进行分析。对珍妮咖啡的需求取决于口味、价格、收入以及替代品价格等因素，比如连锁咖啡店的咖啡。珍妮咖啡的供给则受生产成本，尤其是咖啡豆成本的影响。
A rise in the cost of beans reduces supply — the supply curve shifts to the left. At any given price, Jenny is now willing to supply less coffee unless she can charge a higher price. This initial change explains why she is thinking about raising prices.
咖啡豆成本上升会减少供给——供给曲线向左移动。在任何给定的价格下，除非她能收取更高的价格，否则珍妮现在愿意供给的咖啡数量减少了。这种最初的变化解释了为什么她考虑提价。
7. Shifts in Demand and Supply | 需求与供给的变动
Factors other than price can shift the entire demand or supply curve. For Jenny, demand could shift because the chain cafe is a new, closer substitute. If customers see it as a cheaper and equally good alternative, demand for Jenny’s coffee will shift left — people will want less of it at every price.
价格以外的因素会使整条需求或供给曲线发生移动。对于珍妮来说，需求可能会因为连锁咖啡店是一个新的、更便捷的替代品而移动。如果顾客认为它更便宜且品质相当，对珍妮咖啡的需求就会向左移动——在每一价格下，人们想要的咖啡数量都会减少。
Supply has already shifted left due to higher bean prices. We now have two leftward shifts: one in demand and one in supply. The combined effect on equilibrium price is uncertain — supply left pushes price up, demand left pushes price down.
供给已经因咖啡豆价格上涨而向左移动了。现在我们有了两个向左的移动：一个来自需求，一个来自供给。对均衡价格的综合影响是不确定的——供给向左推高价格，需求向左压低价格。
8. Price Mechanism and Equilibrium | 价格机制与均衡
The market equilibrium price is where quantity demanded equals quantity supplied. In Jenny’s case, the final effect on price depends on the relative size of the shifts. If the supply shock is larger, price may rise. If the demand fall is larger, she may have to cut her price instead.
市场均衡价格是需求量等于供给量时的价格。在珍妮的案例中，对价格的最终影响取决于移动的相对幅度。如果供给冲击更大，价格可能会上升。如果需求下降更大，她可能反而得降低价格。
Let us imagine some numbers:
| Scenario 场景 | Demand shift 需求移动 | Supply shift 供给移动 | Likely equilibrium price 可能的均衡价格 |
|---|---|---|---|
| Bean costs rise sharply 咖啡豆成本大幅上升 | Small left shift 小幅左移 | Large left shift 大幅左移 | Price increases 价格上涨 |
| Chain cafe attracts most customers 连锁店吸引多数顾客 | Large left shift 大幅左移 | Small left shift 小幅左移 | Price decreases 价格下降 |
This shows why Jenny must gather real-world data before deciding. Theory alone cannot predict the outcome without knowing the size of the shifts.
这说明了为什么珍妮在做出决定之前必须收集真实数据。在不知道移动幅度的情况下，光靠理论无法预测结果。
9. Government Intervention: Subsidies for Coffee Farmers | 政府干预：对咖啡农的补贴
Sometimes the government steps in to help local businesses. Imagine the government offers a subsidy to coffee bean farmers, lowering input costs for cafes like Jenny’s. A subsidy shifts the supply curve to the right, as it reduces the cost of production.
有时政府会介入帮助本地企业。假设政府向咖啡豆种植者提供补贴，从而降低了像珍妮这样的咖啡馆的投入成本。补贴会使供给曲线向右移动，因为它降低了生产成本。
In Jenny’s case, a subsidy could offset the increase in bean prices. If the subsidy is large enough, supply might even shift back to its original position. This would allow her to keep prices steady while maintaining profit margins.
在珍妮的案例中，补贴可以抵消咖啡豆价格的上涨。如果补贴足够大，供给甚至可能移回原来的位置。这将使她能在维持利润率的同时保持价格稳定。
10. Evaluation: Winners and Losers | 评估：赢家与输家
Economic decisions create winners and losers. If Jenny raises prices, she might maintain profit but risk losing customers. If she absorbs the cost, customers win through stable prices, but Jenny may earn lower profits and might have to reduce staff hours.
经济决策会创造赢家和输家。如果珍妮提高价格，她可能维持利润，但要冒着失去顾客的风险。如果她自行消化成本，顾客因价格稳定而获利，但珍妮的利润可能降低，或许不得不减少员工工时。
If the government provides a subsidy, taxpayers bear the cost. So even a ‘good’ policy has an opportunity cost. A strong case study answer always ends with evaluation — discussing both sides and finishing with a justified conclusion.
如果政府提供补贴，纳税人将承担成本。因此，即便是“好”的政策也有机会成本。一个出色的案例分析答案总是以评估结尾——讨论双方观点，并以一个有理有据的结论收尾。
11. Practice Case: Online Streaming Services | 实践案例：在线流媒体服务
Now you try one. Scenario: Streamify is a popular platform for movies. A rival, WatchNow, enters the market with a cheaper subscription. At the same time, the cost of data servers, used by both platforms, falls significantly due to new technology. Analyse the likely impact on the equilibrium subscription price for Streamify.
现在你来试一试。场景：Streamify 是一个流行的电影平台。竞争对手 WatchNow 带着更便宜的订阅价格进入市场。与此同时，由于新技术，两家平台都使用的数据服务器的成本显著下降。请分析这对 Streamify 均衡订阅价格可能产生的影响。
Use the following steps:
1. Identify shifts: New rival reduces demand for Streamify (left shift). Cheaper servers increase supply for both platforms (right shift for Streamify).
2. Think about relative size: If demand falls a lot, price may drop. If supply increase is huge, price may also fall. In this case, both forces push price down.
3. Conclude: The subscription price is very likely to decrease.
请使用以下步骤：
1. 识别移动：新竞争对手减少了对 Streamify 的需求（左移）。更便宜的服务器增加了两家平台的供给（Streamify 供给右移）。
2. 思考相对幅度：如果需求下降很多，价格可能下跌。如果供给增加巨大，价格也可能下跌。在这个例子中，两股力量都推动价格下降。
3. 得出结论：订阅价格很可能下降。
12. Key Skills for Case Study Exams | 案例考试的关键技能
To excel in CAIE Year 9 case studies, always read the extract twice. Highlight economic vocabulary like ‘cost,’ ‘income,’ ‘choice,’ ‘substitute,’ and ‘government.’ Then, link each observation to a diagram or concept. Finally, write a conclusion that weighs up the evidence rather than just describing it.
要在 CAIE 九年级案例分析中胜出，总是要读两遍摘录。划出像“成本”、“收入”、“选择”、“替代品”和“政府”这样的经济词汇。然后，将每个观察与图表或概念联系起来。最后，写一个权衡证据的结论，而不仅仅是描述它。
Common mistakes include forgetting to define terms, missing the opportunity cost, and only explaining one side of an argument. Practise with the coffee shop and streaming cases, and then create your own scenarios with friends. The more you apply economics to everyday life, the easier case studies become.
常见的错误包括忘记定义术语、忽略了机会成本，以及只解释争论的一方。用咖啡店和流媒体案例进行练习，然后和朋友们一起创建你自己的场景。你越多地将经济学应用于日常生活，案例分析就越容易。
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