📚 Year 9 WJEC Economics: Case Study Practice | Year 9 WJEC 经济：案例分析实战演练
This article provides a step-by-step walkthrough of a typical economics case study for Year 9 students following the WJEC specification. You will learn how to identify key economic concepts, apply them to a realistic scenario, and structure clear answers using evidence from the data. By the end, you will feel confident tackling case study questions in class and on tests.
本文将为学习 WJEC 课程的 Year 9 学生逐步解析一个典型的经济学案例。你将学到如何识别关键经济概念,将其应用到真实情景中,并利用数据组织清晰答案。读完本文,你将更有信心应对课堂和考试中的案例分析题。
1. Getting Started: What Is a Case Study in Economics? | 入门须知:经济学中的案例分析是什么?
A case study is a short story about a real or imaginary business, consumer or government decision. It usually includes data such as prices, costs, sales numbers, or survey results. Your job is to use economic ideas to explain what is happening, why choices are being made, and what might happen next.
案例分析是关于一个真实或虚构的企业、消费者或政府决策的短篇故事。它通常包含价格、成本、销售数量或调查结果等数据。你的任务是用经济学思想解释发生了什么、为什么做出这些选择,以及接下来可能发生什么。
In WJEC Year 9, you will encounter simple case studies linked to topics like scarcity, opportunity cost, factors of production, supply and demand, and the price mechanism. The key is to always refer back to the case facts when writing your answers.
在 WJEC Year 9 课程中,你将遇到与稀缺性、机会成本、生产要素、供需和价格机制等主题相关的简单案例。关键是在答题时始终回顾案例中的事实。
2. Meet the Case: Sam's Smoothie Stall | 案例呈现:Sam 的奶昔小摊
Sam is a Year 10 student who decides to set up a smoothie stall in the local park on Saturdays. She uses her own savings of £50 to buy a second-hand blender (£20), fruit, yogurt and cups. Each smoothie costs £1.20 to make, and she sells it for £3.00. The park is popular on sunny days, but on rainy days very few people visit. There is already one other smoothie seller in the park who charges £2.80 per drink. Sam has to decide whether to run the stall every Saturday or only when the weather forecast is good.
Sam 是一名 Year 10 学生,她决定周六在当地公园开设一个奶昔小摊。她用自己的积蓄 50 英镑购买了一个二手搅拌机(20 英镑)、水果、酸奶和杯子。每杯奶昔的制作成本为 1.20 英镑,她以 3.00 英镑的价格出售。晴天时公园很热闹,但雨天很少有人来。公园里已经有一位奶昔卖家,每杯售价 2.80 英镑。Sam 必须决定是每周六都出摊,还是只在天气预报好时才出摊。
3. Scarcity and Choice: The Starting Point | 稀缺与选择:一切的开端
Sam has limited resources: only £50 savings, a few hours each Saturday, and one blender. Because her money, time and equipment are scarce, she cannot do everything. She has to make a choice—should she spend her savings on the stall, or keep the money for something else? In economics, scarcity forces everyone to choose between alternatives.
Sam 的资源有限:只有 50 英镑积蓄、每周六几个小时以及一台搅拌机。因为她的资金、时间和设备都是稀缺的,她无法做所有事。她必须做出选择——是把积蓄花在小摊上,还是留着钱做别的事?在经济学中,稀缺性迫使每个人在不同选项之间做出选择。
From the case, Sam chooses to use her savings for the stall. This is her first economic decision. The data shows she spends £20 on the blender immediately, leaving £30 for other inputs.
从案例中看,Sam 选择将积蓄用于小摊。这是她的第一个经济决策。数据显示她立即花费 20 英镑购买搅拌机,剩余 30 英镑用于其他投入。
4. Opportunity Cost: What Sam Gives Up | 机会成本:Sam 放弃了什么
When Sam chooses to start her business, she gives up the next best alternative. The opportunity cost is the value of what she forgoes. Perhaps the £50 could have been saved towards a new phone, or she could have used her Saturdays to study or work part-time elsewhere. The case does not tell us exactly what she gave up, but we can say the opportunity cost includes the lost savings and the lost leisure or earning time.
当 Sam 选择创业时,她放弃了次优选择。机会成本就是她所放弃的东西的价值。也许这 50 英镑本来可以攒着买新手机,或者她可以利用周六学习或做其他兼职。案例没有明确说明她放弃了什么,但我们可以说,机会成本包括失去的积蓄和失去的休闲或赚钱时间。
In your answer, always state clearly what is given up. For example: 'The opportunity cost of Sam starting the smoothie stall is the interest she could have earned from saving the money, plus the alternative use of her Saturday time.'
在你的答案中,务必清晰地说明放弃了什么。例如: “Sam 开设奶昔小摊的机会成本是她存钱本可以获得的利息,加上她周六时间的其他用途。”
5. Factors of Production: Resources Behind the Stall | 生产要素:小摊背后的资源
Every business needs four factors of production: land, labour, capital and enterprise. In Sam's case, the land is the spot in the park where she sets up (a natural resource). Labour is her own effort in making and selling smoothies. Capital includes her blender and the stall table – these are man-made goods used to produce other goods. Enterprise is Sam herself, as she organises the other factors and takes the risk.
每个企业都需要四种生产要素:土地、劳动、资本和企业家才能。在 Sam 的例子中,土地是她在公园摆摊的地点(一种自然资源)。劳动是她自己制作和销售奶昔所付出的努力。资本包括她的搅拌机和摊位桌——这些都是用于生产其他商品的人造物品。企业家才能是 Sam 本人,因为她组织其他要素并承担风险。
Notice that the fruit and yogurt are not capital; they are raw materials used up in production. This distinction often appears in WJEC questions.
注意,水果和酸奶不是资本;它们是生产过程中消耗的原材料。这一区别经常出现在 WJEC 考题中。
6. Costs, Revenue and Profit: Crunching the Numbers | 成本、收入与利润:数字运算
From the case, one smoothie sells for £3.00 and costs £1.20 to make. So the profit per smoothie is:
Profit per unit = Selling price − Cost per unit = £3.00 − £1.20 = £1.80
从案例来看,每杯奶昔售价 3.00 英镑,成本 1.20 英镑。因此每杯利润为:
单位利润 = 售价 − 单位成本 = 3.00 英镑 − 1.20 英镑 = 1.80 英镑
Sam's initial fixed cost was the £20 blender. If she sells only 10 smoothies in a day, her total revenue is 10 × £3 = £30, total variable cost is 10 × £1.20 = £12, and total profit before the blender cost is £18. After covering the blender, her net profit from that day is −£2 (a loss). But if she sells 20 smoothies, she earns £60 revenue, £24 variable cost, giving a surplus of £36, and after the blender cost her profit becomes £16. This shows how sales volume affects success.
Sam 的初始固定成本是 20 英镑的搅拌机。如果她一天只卖出 10 杯奶昔,总收入为 10 × 3 = 30 英镑,总可变成本为 10 × 1.20 = 12 英镑,减去搅拌机成本前的利润为 18 英镑。扣除搅拌机成本后,当天净利润为 −2 英镑(亏损)。但如果她卖出 20 杯,收入为 60 英镑,可变成本 24 英镑,剩余 36 英镑,扣除搅拌机成本后利润为 16 英镑。这说明销量如何影响经营成败。
7. Price and Competition: The Market Environment | 价格与竞争:市场环境
Sam's main competitor sells smoothies at £2.80, which is 20p cheaper than Sam's £3.00. Price is a key factor in a buyer's decision, especially in a park where customers may not be strongly loyal. Sam must consider whether customers are willing to pay 20p more for her smoothies, or whether she needs to match or undercut the rival's price.
Sam 的主要竞争对手以 2.80 英镑的价格出售奶昔,比 Sam 的 3.00 英镑便宜 20 便士。价格是购买决策中的关键因素,尤其是在公园这种顾客忠诚度不高的地方。Sam 必须考虑顾客是否愿意为她的奶昔多付 20 便士,或者她是否需要将价格降至与对手持平或更低。
If Sam lowers her price to £2.80, her profit per smoothie falls to £1.60. She then needs to sell more units to cover the blender cost. This is a classic trade-off between price and quantity demanded.
如果 Sam 把价格降到 2.80 英镑,每杯利润将降至 1.60 英镑。那么她需要卖出更多杯才能覆盖搅拌机成本。这是价格与需求量之间的典型权衡。
8. Demand Factors: Weather and Consumer Behaviour | 需求因素:天气与消费者行为
The case clearly states that park visits depend heavily on weather. This means demand for smoothies is influenced by an external factor (weather) outside Sam's control. On sunny days, demand is high; on rainy days, demand falls sharply. This is a shift in the demand curve, not just a movement along it.
案例明确指出,公园的客流量很大程度上取决于天气。这意味着奶昔的需求受到 Sam 无法控制的外部因素(天气)的影响。晴天需求量高;雨天需求量急剧下降。这是需求曲线的移动,而不仅仅是沿曲线移动。
If Sam decides to operate only when the forecast is good, she reduces the risk of losses but also loses the chance to earn on surprisingly sunny days that were forecast to be rainy. This is a risk-management decision.
如果 Sam 决定只在天气预报好时出摊,她降低了亏损风险,但也可能错过预报有雨却意外晴天的赚钱机会。这是一个风险管理决策。
9. Supply Decisions: How Many Smoothies to Prepare? | 供给决策:准备多少奶昔?
Sam must decide how much stock to bring each Saturday. If she brings too many ingredients, unsold fruit and yogurt may spoil, causing waste and loss. If she brings too little, she misses sales and disappointed customers. The quantity she supplies depends on her expectation of demand, which in turn depends on the weather forecast, competition, and perhaps special events in the park.
Sam 必须决定每个周六带多少原料。如果带得太多,未售出的水果和酸奶可能会变质,造成浪费和损失。如果带得太少,她会错失销售机会并令顾客失望。她供应的数量取决于她对需求的预期,而需求预期又取决于天气预报、竞争状况,或许还有公园内的特殊活动。
This illustrates the basic supply principle: producers offer more when they expect higher prices or greater demand. Sam might prepare 30 portions on a sunny forecast Saturday but only 10 on a cloudy forecast.
这体现了基本的供给原则:当生产者预期价格更高或需求更大时,他们会提供更多数量。Sam 可能在预报晴天的周六准备 30 份,而在预报阴天时只准备 10 份。
10. The Price Mechanism in Action | 价格机制的实际运作
The park smoothie market shows how prices coordinate buyers and sellers. If Sam sets her price too high relative to the competitor, she may lose customers. If demand surges on a hot day and the other stall runs out, Sam could perhaps raise her price a little and still sell out. The price mechanism allocates scarce goods (smoothies) to those willing and able to pay.
公园的奶昔市场展示了价格如何协调买卖双方。如果 Sam 的价格相对于竞争对手定得过高,她可能失去顾客。如果在炎热的一天需求激增而另一家摊位卖完了,Sam 或许可以稍微提价却依然售罄。价格机制将稀缺商品(奶昔)分配给那些愿意并且有能力支付的人。
WJEC expects you to use phrases like 'price acts as a signal', 'incentive to producers' and 'rationing function of price'. In this case, the existing competitor's lower price signals that Sam must offer something extra (taste, portion size, branding) to justify the higher price.
WJEC 要求你使用诸如“价格作为信号灯”、“对生产者的激励”和“价格的配给功能”等表述。在这个案例中,竞争对手的低价传递出信号:Sam 必须提供额外价值(口味、份量、品牌)才能支撑其较高价格。
11. Exam-Style Questions and Model Answers | 考试风格题目与范文答案
Let's apply what we've covered to some typical WJEC case study questions.
让我们将所学应用到一些典型的 WJEC 案例分析题中。
Q1: Identify two scarce resources Sam faces. (2 marks)
- Money – she has only £50 savings to invest. / 资金——她只有 50 英镑积蓄可以投入。
- Time – she can only operate on Saturdays for a few hours. / 时间——她只能在周六的几小时内经营。
Q2: Explain one opportunity cost of Sam's decision to start the stall. (3 marks)
One opportunity cost is the alternative use of her savings. The £50 could have been deposited in a savings account earning interest, or spent on a personal item. By choosing the stall, she gives up the benefit from that next best alternative.
一个机会成本是她积蓄的其他用途。这 50 英镑本可以存入储蓄账户获得利息,或用于购买个人物品。选择开小摊,她就放弃了那次优选项带来的益处。
Q3: Using the data, calculate Sam's total profit if she sells 25 smoothies. (3 marks)
Total revenue = 25 × £3 = £75. Total variable cost = 25 × £1.20 = £30. Gross profit = £75 − £30 = £45. Net profit = £45 − £20 (blender) = £25.
总收入 = 25 × 3 = 75 英镑。总可变成本 = 25 × 1.20 = 30 英镑。毛利润 = 75 − 30 = 45 英镑。净利润 = 45 − 20(搅拌机)= 25 英镑。
12. Top Tips for Your Own Case Study Practice | 实战演练的高分技巧
Always read the case material twice. Highlight numbers, resources, choices and any changes in conditions. Before writing, decide which economic concept fits each paragraph (scarcity, opportunity cost, demand, etc.). Use the phrase 'from the case' or 'the data shows' to prove you are applying context.
务必阅读案例材料两遍。标出数字、资源、选择以及条件变化。动笔前,先确定每个段落适用的经济概念(稀缺性、机会成本、需求等)。使用“从案例来看”或“数据显示”等措辞,以证明你在结合情景分析。
Practice writing clear, concise explanations that link theory to the specific facts. Even a simple stall can illustrate complex ideas. With regular practice, you will master the WJEC case study approach.
练习写出清晰、简明的解释,将理论与具体事实联系起来。即使是一个简单的小摊也能阐释复杂的经济思想。通过定期练习,你将掌握 WJEC 案例分析的解题方法。
Published by TutorHao | Economics Revision Series | aleveler.com
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