📚 Case Study Practical Exercises | 案例分析实战演练
Economics is not just about theories; it’s about understanding real-world situations. This article provides a series of case study exercises designed for Year 7 OCR Economics students to apply key concepts like scarcity, choice, opportunity cost, and market forces. Each case study presents a scenario, followed by analysis and questions to test your understanding.
经济学不仅仅是理论，更是理解现实世界的情境。本文提供一系列案例分析练习，专为7年级OCR经济学生设计，用以应用稀缺性、选择、机会成本以及市场力量等关键概念。每个案例研究展示一个场景，随后进行分析并提出问题以检验你的理解。
1. Case Study Approach | 案例分析方法
When tackling any case study, start by identifying the fundamental economic problem. This almost always links back to the idea of scarcity – there are not enough resources to satisfy all wants and needs. Look for the decision-maker: an individual, a business, or a government. Then work out what choices they face because of limited time, money, or materials.
解决任何案例时，首先要识别基本的经济问题。这几乎总是与稀缺性概念相关——没有足够的资源来满足所有的欲望和需求。找到决策者：个人、企业或政府。然后弄清楚他们由于有限的时间、金钱或材料而面临什么选择。
The next step is to identify the opportunity cost of each possible decision. Opportunity cost is the next best alternative that you give up when a choice is made. Since resources are scarce, choosing one thing means we cannot have something else. Good economists always ask ‘what is being sacrificed?’
下一步是确定每个可能决策的机会成本。机会成本是你做出选择时所放弃的次优替代品。由于资源是稀缺的，选择一样东西意味着我们不能拥有其他东西。优秀的经济学家总会问“牺牲的是什么？”
Finally, consider the incentives that shape people’s behaviour. A reward or a penalty can change the way individuals act. After analysing the outcome, reflect on whether the decision was efficient and whether any unintended consequences arose. This method will help you break down any economic puzzle.
最后，考虑塑造人们行为的激励因素。奖励或惩罚可以改变个人的行为方式。在分析结果之后，反思这个决策是否有效率，以及是否出现了任何意外后果。这个方法将帮助你拆解任何经济学谜题。
2. Case 1: Scarce Island Resources | 案例1：稀缺的岛屿资源
Imagine you are stranded on a small island with only a few basic tools. You have 8 hours of daylight each day to work. You can use this time either to catch fish or to gather coconuts. In one hour, you can catch 2 fish or gather 10 coconuts. Your survival depends on dividing your time wisely.
想象你被困在一个小岛上，只有一些基本工具。你每天有8小时的日光用于劳动。你可以用这些时间捕鱼或摘椰子。一小时你能捕到2条鱼或摘到10个椰子。你的生存取决于明智地分配时间。
The island’s resources (your labour, the fish, the coconut trees) are scarce relative to your wants – you want food, shelter, and leisure. Every hour spent fishing means 2 fish gained but 10 coconuts lost. The opportunity cost of catching 2 fish is 10 coconuts. If you choose to spend 3 hours fishing and 5 hours gathering coconuts, you will get 6 fish and 50 coconuts. The unseen cost is the coconuts or fish you did not produce.
相对于你的需求（你想要食物、住所和休闲），岛屿的资源（你的劳动、鱼、椰子树）是稀缺的。花在捕鱼上的每一个小时意味着获得2条鱼但失去10个椰子。捕2条鱼的机会成本是10个椰子。如果你选择花3小时捕鱼和5小时摘椰子，你会得到6条鱼和50个椰子。看不见的成本是你没有生产的椰子或鱼。
Question: If you decide to spend 7 hours fishing and only 1 hour gathering coconuts, what is the opportunity cost of the extra fish? What essential item might you lack? Think about the trade-off.
问题：如果你决定花7小时捕鱼而只花1小时摘椰子，额外鱼只的机会成本是什么？你可能会缺乏什么必需品？想一想取舍。
3. Case 2: The Weekend Time Dilemma | 案例2：周末时间的抉择
As a student, you have exactly 6 hours of free time on Saturday after finishing homework. You want to use this time in three ways: playing online games, revising for an economics test, and playing football with friends. You rank these activities by enjoyment, but you also care about your grade. Economists call this a ‘time budget’ problem.
作为一名学生，你在周六完成作业后有恰好6小时的自由时间。你想用三种方式利用这段时间：玩网络游戏、复习经济学测验以及与朋友踢足球。你按享受程度对这些活动进行排序，但你也关心成绩。经济学家称此为“时间预算”问题。
Suppose each hour spent gaming gives you high pleasure but no improvement in test scores. Each hour of revision raises your potential mark by 5 points but gives little joy. Football provides exercise and social fun but no direct academic benefit. The true cost of 2 hours of gaming is not just the time lost – it is the 10-point test improvement you sacrificed, or the football match you missed.
假设每玩一小时游戏给你带来很高的愉悦感，但对测验成绩没有提升。每一小时复习能使你的潜在分数提高5分，但几乎没有乐趣。踢足球提供锻炼和社交乐趣，但没有直接的学业收益。玩2小时游戏的真正成本不仅仅是失去的时间——而是你牺牲的10分测验提升，或者你错过的足球比赛。
Create your own combination of 6 hours. What is the opportunity cost if you choose zero revision hours? Could there be a balanced solution where you gain some enjoyment and some grade improvement? Remember that rationality means making the best use of scarce time to achieve your goals.
创建你自己的6小时组合。如果你选择零复习时间，机会成本是什么？是否能有一个平衡的解决方案，让你获得一些享受和一些成绩提升？记住，理性意味着最好地利用稀缺时间来实现你的目标。
4. Case 3: Starting a Lemonade Stand | 案例3：创业卖柠檬水
You decide to set up a lemonade stand outside your house during the summer. To produce lemonade, you need factors of production: land (the pavement spot), labour (your effort and a friend’s help), capital (a table, cups, a pitcher, and lemons), and entrepreneurship (your idea and willingness to take the risk). Each factor has a cost.
你决定夏天在屋外摆一个柠檬水摊。要生产柠檬水，你需要生产要素：土地（人行道上的位置）、劳动（你的努力和一个朋友的帮助）、资本（桌子、杯子、一个大水壶和柠檬），以及企业家才能（你的创意和承担风险的意愿）。每个要素都有成本。
You buy 20 lemons for £4, a bag of sugar for £2, and use a pitcher your family already owns (implicit cost). You estimate you can sell 40 cups at £0.50 each. Your total revenue would be £20. The explicit costs (lemons + sugar) are £6, leaving an accounting profit of £14. However, you and your friend work 4 hours each – if you could have earned £3 per hour doing a different job, the total opportunity cost of your labour is £24. The economic profit becomes negative.
你花4英镑买了20个柠檬，2英镑买了一袋糖，并使用家里已有的水壶（隐性成本）。你估计能以每杯0.50英镑的价格卖出40杯。你的总收入将是20英镑。显性成本（柠檬+糖）为6英镑，留下会计利润14英镑。但你和你的朋友各工作了4小时——如果你们做其他工作每小时能赚3英镑，你们劳动的总机会成本就是24英镑。经济利润变为负值。
This case shows that profit seen on paper may not be the whole story. Entrepreneurs must weigh all opportunity costs before deciding if a business idea is worthwhile. What improvements could you make to increase sales or reduce costs?
这个案例表明，账面上的利润可能不是全部情况。企业家在决定一个商业想法是否值得之前，必须权衡所有的机会成本。你可以做出哪些改进来增加销售或降低成本？
5. Case 4: The Canteen Pizza Problem | 案例4：食堂披萨风波
Your school canteen sells slices of pizza for £1.50 each. Typically, at this price, students buy 80 slices per day. When the canteen raised the price to £2.00, the number of slices sold dropped to 50. When they cut the price to £1.00 for a special offer, sales jumped to 120 slices. This demonstrates the law of demand: as price rises, the quantity demanded tends to fall, ceteris paribus (all other things being equal).
你的学校食堂以每片1.50英镑的价格出售披萨。通常，在这个价格下，学生每天购买80块。当食堂将价格提高到2.00英镑时，售出的数量下降到50块。当他们在特别优惠中将价格降至1.00英镑时，销量跃升至120块。这展示了需求定律：在其他条件相同的情况下，随着价格上涨，需求量倾向于下降。
But what could shift the entire demand curve? If the school introduces a popular alternative, like hot dogs at £1.00, pizza demand may fall at every price. If students’ pocket money increases on average, pizza demand may rise because it is a normal good. Tastes also matter: if a health campaign turns students against pizza, demand will shrink. Consider these factors when forecasting how many pizzas the canteen should prepare.
但什么会移动整条需求曲线呢？如果学校推出一种受欢迎的替代品，比如1.00英镑的热狗，披萨的需求在每一个价格下都可能会下降。如果学生的零花钱平均提高，披萨的需求可能上升，因为它是一种正常商品。口味也很重要：如果一项健康宣传活动让学生们反感披萨，需求就会萎缩。在预测食堂应准备多少披萨时，请考虑这些因素。
Question: Suppose the canteen wants to sell exactly 100 slices. Based on the data, what price might achieve that? Is the relationship between price and quantity always linear? Explain your reasoning.
问题：假设食堂想恰好卖出100块披萨。根据数据，什么价格可能达到这个目标？价格与数量之间的关系总是线性的吗？解释你的推理。
6. Case 5: Uncovering Toy Prices | 案例5：玩具价格大揭秘
A new robot toy is launched just before the holiday season. Shops have only 200 units in stock, but hundreds of families want to buy it. The high demand and limited supply push the price up to £45. Some parents are willing to pay even more because the toy is the ‘must-have’ item of the year. This is a classic example of excess demand creating upward pressure on price.
一款新的机器人玩具在节日前发布。商店只有200件库存，但数百个家庭想购买。高需求和有限的供应将价格推至45英镑。一些家长甚至愿意付更多，因为这款玩具是年度“必备品”。这是超额需求造成价格上涨压力的经典例子。
Three months later, the factory increases production, and shops receive 800 more units. Meanwhile, the holiday excitement has faded, and a newer game console distracts people. The equilibrium price falls to £25. Retailers who still charge £35 find themselves with unsold stock. The market moves towards a new equilibrium where quantity supplied matches quantity demanded.
三个月后，工厂增加生产，商店又多收到了800件。同时，节日的兴奋感已消退，一款更新的游戏机分散了人们的注意力。均衡价格降至25英镑。仍收取35英镑的零售商会发现自己有未售出的库存。市场趋向一个新的均衡，供给量与需求量相匹配。
Identify the factors that shifted supply and demand in this case. What would happen if the manufacturer had kept production at the original level? Draw a mental picture of the market adjusting, and try to predict what might happen next year when a new version is rumoured.
找出这个案例中移动供给和需求的因素。如果制造商把生产维持在最初水平，会发生什么？在脑海中绘制市场调整的图景，并尝试预测当传闻明年将推出新版本时会发生什么。
7. Case 6: The Classroom Trading Game | 案例6：班级的交易游戏
Your class is split into two groups: Group A can produce either 30 posters or 15 podcast scripts in an hour. Group B can produce either 20 posters or 20 podcast scripts in the same time. At first glance, Group A seems better at both tasks, but economists look at comparative advantage – the ability to produce a good at a lower opportunity cost.
你的班级被分成两组：A组每小时可以制作30张海报或15份播客脚本。B组在同样时间内可以制作20张海报或20份播客脚本。乍一看，A组两项任务都更擅长，但经济学家看的是比较优势——以更低的机会成本生产一种商品的能力。
For Group A, the opportunity cost of 1 poster is 0.5 scripts. For Group B, the opportunity cost of 1 poster is 1 script. So Group A has a comparative advantage in posters. Conversely, Group B’s opportunity cost of 1 script is 1 poster, while for Group A it is 2 posters. Group B has a comparative advantage in scripts. By specialising – Group A makes only posters, Group B makes only scripts – and trading, both groups can end up with more posters and scripts than if they had tried to produce everything themselves.
对于A组，1张海报的机会成本是0.5份脚本。对于B组，1张海报的机会成本是1份脚本。所以A组在海报上有比较优势。相反，B组1份脚本的机会成本是1张海报，而A组是2张海报。B组在脚本上有比较优势。通过专业化——A组只做海报，B组只做脚本——并进行交易，两组都能得到比他们试图自己生产所有东西时更多的海报和脚本。
This game shows how specialisation and trade can increase total output. Apply this to real countries: why does one nation export wheat while another exports electronics? Even if one country is more efficient at everything, trade still benefits both sides.
这个游戏展示了专业化和贸易如何增加总产出。将其应用到真实的国家：为什么一个国家出口小麦而另一个国家出口电子产品？即使一个国家在所有方面都更有效率，贸易仍能使双方受益。
8. Case 7: Litter in the Park | 案例7：公园的垃圾问题
A beautiful public park is used by hundreds of visitors every weekend. However, many people leave empty cans and crisp packets on the grass. The mess spoils the park for others, and the council spends £500 per week on cleaning. The private cost to a litterbug is almost zero – just a moment of convenience. But the social cost includes the unpleasant environment and the tax money spent on the cleanup. This is a negative externality.
一个美丽的公共公园每周末被数百名游客使用。然而，许多人把空罐子和薯片包装袋留在草地上。这些垃圾破坏了公园的环境，市政委员会每周花费500英镑进行清洁。乱扔垃圾者的私人成本几乎为零——只是一时的便利。但社会成本包括令人不快的环境和用于清洁的税款。这是一种负外部性。
Because the park is a common resource, no one is excluded from using it, and there is little incentive for individuals to take their litter home. The result is market failure: the free market left alone will produce too much litter. Possible solutions include placing more bins, introducing fines for littering, or running educational campaigns. Each solution has costs and benefits.
因为公园是一种公共资源，不排斥任何人使用，个人几乎没有动力把垃圾带回家。结果是市场失灵：放任自由市场会产生过多的垃圾。可能的解决方案包括放置更多垃圾桶、对乱扔垃圾者引入罚款，或开展教育活动。每种解决方案都有成本和收益。
If a £50 fine is introduced and strictly enforced, do you think the amount of litter will fall to an optimal level? What unintended consequences might arise, such as people avoiding the park altogether? Analyse the incentives at play.
如果引入50英镑的罚款并严格执行，你认为垃圾数量会降至最优水平吗？可能出现什么意外后果，比如人们干脆不去公园了？分析其中起作用的激励。
9. Case 8: The School’s New Rule | 案例8：学校的新规定
To reduce lateness, your school introduces a new rule: any student who arrives after 8:45 a.m. must stay for a 30-minute detention after school. Previously, about 15% of students were late each day. After one month, that figure dropped to 5%. The penalty changed the incentive structure; the cost of being late increased, so students made more effort to be on time.
为减少迟到，你的学校推出新规定：早上8:45之后到达的任何学生必须在放学后留校30分钟。此前，每天约有15%的学生迟到。一个月后，这一比例降至5%。惩罚改变了激励结构；迟到的成本增加了，所以学生更加努力地要求自己准时。
But also consider the unintended effects. Some students now rush dangerously to avoid detention, leading to a few minor accidents. Others who live far away feel the rule is unfair and become disgruntled. The school could have used a reward instead: a golden ticket for those on time all month, which enters them in a prize draw. Which system would be more effective and why?
但也要考虑意外后果。一些学生现在为了逃避拘留而危险地奔跑，导致了几起小事故。其他住得远的学生觉得这个规定不公平，变得不满。学校本可以采用奖励代替：对那些整个月都准时的学生发放金票，让他们参与抽奖。哪种制度会更有效，为什么？
This case invites you to compare positive incentives (rewards) and negative incentives (penalties). Apply the same logic to government policies, such as taxing sugary drinks to reduce consumption versus subsidising healthy food.
这个案例邀请你比较正向激励（奖励）和负向激励（惩罚）。将同样的逻辑应用于政府政策，比如对含糖饮料征税以减少消费，与补贴健康食品进行比较。
10. Putting It All Together: Your Choice | 综合练习：你的选择
You have inherited a small plot of land from your grandparents. You can use it either to grow organic vegetables or to raise free-range chickens. Seeds, fertiliser, and watering equipment cost £200, and you expect to harvest produce worth £500 in six months. Chickens cost £150 for the coop and chicks, and you could sell eggs and meat worth £450 in the same period. However, raising chickens takes 10 hours of your work per week, whereas the vegetables require only 5 hours. Your time is valuable; you could work a part-time job earning £8 per hour.
你从祖父母那里继承了一小块地。你可以用它来种植有机蔬菜或饲养散养鸡。种子、肥料和浇水设备成本为200英镑，你预期在六个月内收获价值500英镑的农产品。鸡的成本为150英镑用于鸡舍和小鸡，你可以在同期出售价值450英镑的鸡蛋和鸡肉。然而，养鸡每周需要你10小时的劳动，而种菜只需要5小时。你的时间很宝贵；你可以做一份每小时赚8英镑的兼职工作。
Calculate the economic profit for each option. For vegetables: revenue £500 – explicit cost £200 = £300. Opportunity cost of your time: 5 hours x 8 weeks x £8 = £320 (assuming 2 months of care). Economic profit = -£20. For chickens: revenue £450 – explicit cost £150 = £300, but time cost is 10 hours x 8 weeks x £8 = £640, giving an economic loss. The part-time job alone would have earned you £640 or £320 depending on hours, which may be the best use of your labour. Which choice would a rational economic agent make?
计算每个选项的经济利润。对于蔬菜：收入500英镑 – 显性成本200英镑 = 300英镑。你的时间机会成本：5小时 × 8周 × 8英镑 = 320英镑（假设2个月的照料）。经济利润 = -20英镑。对于养鸡：收入450英镑 – 显性成本150英镑 = 300英镑，但时间成本是10小时 × 8周 × 8英镑 = 640英镑，导致经济亏损。单独看兼职工作，根据工时不同将为你赚得640英镑或320英镑，这可能是你劳动的最佳用途。一个理性的经济主体会做何选择？
Now consider a twist: what if the government offers a subsidy of 50p per egg, making the chicken option more profitable? Or if a new supermarket nearby offers to buy all your vegetables at a premium price? Recalculate and decide. This exercise shows how real economic decisions merge concepts of cost, revenue, and incentive.
现在考虑一个转折：如果政府为每枚鸡蛋提供50便士的补贴，使养鸡选项更赚钱？或者如果附近新开的超市愿意以溢价购买你所有的蔬菜？重新计算并做出决定。这个练习展示了真实经济决策如何融合成本、收益和激励的概念。
Published by TutorHao | Economics Revision Series | aleveler.com
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