📚 Case Study Practice in Year 7 Economics | 七年级经济案例分析实战演练
In Year 7 Economics, one of the best ways to understand how people make decisions is to work through a real-life case study. This article will take you step by step through a simple scenario, helping you apply core concepts such as scarcity, choice, opportunity cost, incentives, demand and supply. By the end, you will feel confident tackling any case study question in your CIE checkpoint assessment.
在七年级经济学中，理解人们如何做出决策的最佳方法之一就是通过真实案例来进行演练。本文将一步步带你分析一个简单的情境，帮助你运用稀缺性、选择、机会成本、激励、需求与供给等核心概念。读完本文后，你将更有信心应对 CIE 阶段性评估中的任何案例分析题。
1. Meet Amy and Her Saturday Dilemma | 认识艾米和她的周六难题
Amy is a Year 7 student. Every Saturday she receives £10 pocket money. This weekend, she has four hours of free time in the afternoon. She must decide how to spend both her money and her time. At the moment, two options excite her: watching a new film at the cinema (£8 per ticket, and the whole trip takes 3 hours) or buying a mystery novel (£7, which she can start reading immediately, and she estimates it will take about 2 hours to finish a few chapters). There is also a third option: she could go to the local park with her dog, which costs nothing and takes 2 hours.
艾米是一名七年级学生。每个周六她都会得到 10 英镑零花钱。这个周末，她下午有四个小时的空闲时间。她必须决定如何支配自己的金钱和时间。眼下有两个选项让她心动：去电影院看一部新电影（票价 8 英镑，来回和观影共需 3 小时），或者购买一本悬疑小说（7 英镑，买回来就可以开始读，她估计读完前几章大约需要 2 小时）。此外还有第三个选项：带着狗去附近公园玩，不花钱，耗时 2 小时。
2. Identifying Scarcity | 识别稀缺性
Scarcity is the basic economic problem: we have unlimited wants but limited resources. Amy wants to enjoy her Saturday, but she has only £10 and 4 hours. Her money and time are both scarce resources. Even if she had more money, she would still face a time limit. Because of scarcity, she cannot do everything she wants; she must make a choice.
稀缺性是经济学的基本问题：我们有无限的需求，但资源有限。艾米想要享受周六，但她只有 10 英镑和 4 小时。她的金钱和时间都是稀缺资源。即使她有更多的钱，她依然面临时间上的限制。由于存在稀缺性，她无法做所有想做的事情，必须做出选择。
3. Making a Choice and Facing Trade-offs | 做出选择与面对取舍
Amy lists her options clearly. Option A: cinema – costs £8 and 3 hours. Option B: buy a book – costs £7 and 2 hours. Option C: park with dog – costs £0 and 2 hours. She can only pick one primary activity because her time blocks overlap. If she chooses the cinema, she gives up the book and the park. This giving up of alternatives is called a trade-off. Every choice involves trade-offs.
艾米清楚列出了自己的选项。选项 A：看电影——花费 8 英镑和 3 小时。选项 B：买书——花费 7 英镑和 2 小时。选项 C：带狗去公园——花费 0 英镑，耗时 2 小时。她只能选择一个主要活动，因为时间区块是重叠的。如果她选择电影院，就得放弃书和公园。这种放弃其他选项的行为就叫做取舍。每一个选择都伴随着取舍。
4. Opportunity Cost: The Next Best Alternative Given Up | 机会成本：放弃的次优选择
The opportunity cost of a decision is the value of the next best alternative forgone. If Amy chooses the cinema, she cannot buy the book or go to the park. Her next best alternative might be the book because it gives her hours of enjoyment and she loves reading. So the opportunity cost of watching the film is the enjoyment and knowledge she would have gained from the mystery novel, plus the £1 saved. Notice that opportunity cost is not simply money; it includes experience and satisfaction.
一项决策的机会成本是所放弃的次优选择的价值。如果艾米选择看电影，她就不能买书或去公园。她的次优选择可能是那本书，因为读书能带给她好几个小时的乐趣，而且她热爱阅读。因此，看电影的机会成本是她本可以从悬疑小说中获得的快乐和知识，再加上省下的 1 英镑。请注意，机会成本不仅仅是金钱，它还包括体验和满足感。
5. Incentives Can Change Decisions | 激励因素会改变决策
An incentive is something that motivates a person to act. Suppose Amy's best friend texts her: 'Come to the cinema with me – my mum will pay for your ticket!' Now the money cost drops to £0, and she gets to spend time with a friend. The incentive of a free ticket and companionship makes the cinema much more attractive. The opportunity cost would now only be the time lost (3 hours) and the book she still could not buy, but she could still read a borrowed book later. Incentives influence our choices by altering the benefits or costs.
激励是指推动人们行动的因素。假设艾米最好的朋友发来消息：“一起去电影院吧——我妈妈请你看电影！”这样一来，金钱成本降为零，而且她还能和朋友共度时光。免费电影票和陪伴这一激励因素使得电影院变得极具吸引力。此时机会成本仅仅是她损失的时间（3小时）以及依然无法购买的那本书，不过她以后可以借书来读。激励因素通过改变收益或成本来影响我们的选择。
6. Introducing Demand: How Much Would Amy Pay? | 引入需求：艾米愿意付多少钱？
Demand shows the quantity of a good or service that a consumer is willing and able to buy at different prices. Before the friend's offer, at a price of £8, Amy was willing to buy one cinema ticket. If the ticket price rose to £10, she would not go because it would use all her pocket money and leave no room for snacks. If the price dropped to £4, she might even go twice a month. This relationship between price and quantity demanded is the law of demand: when price falls, quantity demanded rises, and vice versa.
需求表示消费者在不同价格水平下愿意并且能够购买的商品或服务的数量。在朋友发出邀请之前，当票价为 8 英镑时，艾米愿意购买一张电影票。如果票价涨到 10 英镑，她就不会去，因为那会花光她所有的零花钱，而且没有余钱买零食。如果票价降到 4 英镑，她甚至一个月可能会去看两次。这种价格与需求量之间的关系就是需求定律：价格下降时，需求量上升，反之亦然。
7. Introducing Supply: The Cinema's Perspective | 引入供给：电影院的角度
Supply refers to the quantity of a good that producers are willing and able to offer at different prices. The cinema might have 200 seats per screening. If the ticket price is high, the cinema is willing to offer more screenings because it can cover costs and earn higher profit. If the price were very low, say £2, the cinema might reduce the number of screenings or even close on Saturdays. The law of supply states that as price rises, quantity supplied rises.
供给是指生产者在不同价格下愿意并且能够提供的商品数量。电影院每场放映有 200 个座位。如果票价较高，电影院愿意安排更多场次，因为它能收回成本并获得更高的利润。如果票价非常低，比如 2 英镑，电影院就可能减少排片，甚至周六不营业。供给定律指出，价格上升时，供给量也会上升。
8. Market Equilibrium: Where Demand Meets Supply | 市场均衡：需求与供给相遇之处
In a free market, the interaction of demand and supply determines the price. Imagine the cinema wants to fill its 200 seats. If it sets the price too high at £12, only 80 people might demand tickets. There would be a surplus of 120 empty seats. To fill them, the cinema might lower the price to £8. At that price, perhaps 200 people want to go, matching exactly the number of seats. This point is called market equilibrium. For Amy, the equilibrium price of £8 is exactly what she faces.
在自由市场中，需求与供给的相互作用决定了价格。假设电影院想要坐满 200 个座位。如果票价定得太高，设为 12 英镑，可能只有 80 人会购买电影票，出现 120 个空座的过剩。为了填满空座，电影院可能会把价格降到 8 英镑。在 8 英镑的价格下，也许有 200 人愿意观影，正好与座位数相匹配。这一点就叫做市场均衡。对艾米来说，8 英镑的均衡价格正是她所面对的情况。
9. The Role of Time as a Scarce Resource | 时间作为稀缺资源的作用
Money is not the only scarce resource for Amy. Time also limits her choices. Even if the cinema ticket were free, she still must give up 3 hours of her afternoon. She could have used that time to read the book (2 hours) and still have 2 hours left for the park. The time trade-off shows that opportunity cost can be measured in lost leisure, study, or other activities. This is why economists always consider both monetary and non-monetary costs.
对艾米来说，金钱并非唯一的稀缺资源。时间同样限制着她的选择。即使电影票免费，她仍然必须放弃下午的 3 个小时。她本可以利用这段时间读那本书（2 小时），并且还能剩下 2 小时去公园。时间上的取舍表明，机会成本可以用损失的休闲、学习或其他活动来衡量。这就是经济学家总是同时考虑货币成本和非货币成本的原因。
10. How Preferences Affect Choices | 偏好如何影响选择
Not everyone values options equally. Amy loves reading more than walking the dog, but she also values friendship highly. When her friend invited her, her preferences shifted the decision. Economists say that utility – the satisfaction from a choice – depends on individual tastes. If Amy were an outdoor enthusiast, the park might give her the highest utility. Understanding preferences helps explain why two people with the same budget and time might make very different choices.
并不是每个人都同等地看重各个选项。艾米比遛狗更喜欢阅读，但她也非常看重友谊。当朋友邀请她时，她的偏好改变了决定。经济学家说，效用——即从选择中获得的满足感——取决于个人喜好。如果艾米是一个户外活动爱好者，公园可能会给她带来最大的效用。理解偏好有助于解释为什么预算和时间相同的两个人会做出截然不同的选择。
11. Combining Choices and the Concept of Margin | 组合选择与边际概念
Sometimes we do not have to choose just one thing. Amy could buy the book for £7, read it for 2 hours, and then take the dog to the park for the remaining 2 hours. That combination uses £7 and all 4 hours. The cinema might be left out. Thinking at the margin means considering small changes: 'If I spend one more hour reading, what do I give up?' The marginal benefit of the extra hour must be compared with the marginal cost. Amy's final decision depends on which combination gives her the highest total satisfaction.
有时我们不必只选择一件事。艾米可以花 7 英镑买书，阅读 2 小时，然后用剩下的 2 小时带狗去公园。这个组合花掉 7 英镑并占满全部 4 小时，电影院就被排除在外了。边际思考是指考虑微小的变化：“如果我再多读一小时书，我会放弃什么？”额外一小时的边际收益必须和边际成本进行比较。艾米的最终决定取决于哪种组合能带给她最高的总满足感。
12. Case Study Conclusion: Bringing It All Together | 案例总结：融会贯通
Through Amy's Saturday planning, we have seen scarcity (limited money and time), choice (cinema, book, park), trade-offs, opportunity cost, incentives (free ticket from friend), demand and supply (cinema ticket pricing), equilibrium, and the role of time and preferences. When you face a case study question, always identify the scarce resources, list the alternatives, find the opportunity cost of the chosen option, and discuss any incentives or changes in conditions that might alter the decision. This framework will help you structure clear, logical answers.
通过艾米的周六计划，我们看到了稀缺性（金钱和时间有限）、选择（电影、书、公园）、取舍、机会成本、激励（朋友的免费票）、需求与供给（电影票定价）、均衡，以及时间和偏好的作用。当你面对案例分析题时，记得先找出稀缺资源，列出备选方案，找出所选方案的机会成本，并讨论任何可能改变决策的激励或条件变化。这个框架将帮助你构建清晰、有条理的答案。
Published by TutorHao | Year 7 Economics Revision Series | aleveler.com
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