📚 Year 9 SQA Economics: Case Study Practice in Action | SQA九年级经济学：案例分析实战演练
Case studies are a powerful way to bring economic theory to life. In this article, you will work through a realistic business scenario, applying core concepts such as supply, demand, elasticity and market structures. By the end, you will feel confident in tackling SQA-style case study questions in Year 9 Economics.
案例分析是将经济理论应用于现实的有力方式。在本文中，你将通过一个真实的商业情景，应用供给、需求、弹性和市场结构等核心概念。结束时，你将充满信心地应对九年级经济学中SQA风格的案例分析题。
1. Understanding the Case Study Method | 理解案例分析方法
A case study in economics is a detailed examination of a single firm, market or policy. It requires you to identify key economic principles, analyse data, and suggest solutions. The SQA Year 9 syllabus expects you to extract information from a short passage, a table or a graph, and then use economic vocabulary to explain what is happening.
经济学中的案例研究是对单个企业、市场或政策的详细考察。它要求你识别关键的经济原理，分析数据并提出解决方案。SQA九年级大纲希望你从短文、表格或图表中提取信息，然后用经济学术语解释正在发生的情况。
You will often be asked to 'discuss', 'explain' or 'evaluate'. This means you need to go beyond a simple description. Always link your answer to the specific details in the case material, and where possible, draw a simple demand and supply diagram in your mind to support your reasoning.
你经常会被要求“讨论”、“解释”或“评估”。这意味着你需要超越简单的描述。始终将你的回答与案例材料中的具体细节联系起来，并尽可能在脑海中画一个简单的供需图来支持你的推理。
2. Presenting the Case: The Coffee Corner Dilemma | 案例呈现：咖啡角的困境
Let us dive into our case. 'The Coffee Corner' is a small independent cafe in a busy town. For the past year, it has been selling an average of 100 cups of coffee per day at a price of £2.50 per cup. Its main costs include £80 daily rent, £120 in wages, and £0.80 per cup for coffee beans, milk and cups. The owner, Mia, aims to maximise profit.
让我们进入案例。“咖啡角”是繁忙小镇上的一家小型独立咖啡馆。过去一年里，它平均每天以每杯2.50英镑的价格售出100杯咖啡。它的主要成本包括每日80英镑的租金、120英镑的工资，以及每杯0.80英镑的咖啡豆、牛奶和杯子成本。店主米娅的目标是利润最大化。
A new chain cafe, 'QuickBrew', has just opened across the street. QuickBrew is selling coffee at an introductory price of £1.99 per cup. Within two weeks, The Coffee Corner's daily sales have dropped to 60 cups. Mia is considering whether to lower her price, introduce a loyalty card, or add premium pastries. Meanwhile, the local council is proposing a £0.15 sugar tax on each sugary drink sold.
一家新的连锁咖啡馆“快煮”刚刚在街对面开业。快煮以每杯1.99英镑的推广价出售咖啡。两周内，咖啡角的日销量跌至60杯。米娅正在考虑是降低价格、推出积分卡还是增加优质糕点。同时，当地议会正提议对每份含糖饮料征收0.15英镑的糖税。
3. Identifying the Economic Problem | 确定经济问题
The fundamental economic problem here is scarcity: Mia has limited resources (time, money, ingredients) but faces changing consumer wants. More specifically, this is a case of a shift in market conditions caused by new competition. The economic questions are: How will the entry of QuickBrew affect the demand for The Coffee Corner's coffee? What pricing and non-pricing strategies can Mia use? And how might government intervention alter the outcome?
这里的基本经济问题是稀缺性：米娅拥有有限的资源（时间、金钱、原料），却面临着变化的消费者需求。更具体地说，这是一个由新竞争引发的市场环境变化案例。经济问题是：快煮的进入将如何影响咖啡角咖啡的需求？米娅可以使用哪些定价和非定价策略？政府的干预又将如何改变结果？
In your exam, always begin by naming the economic problem. It could be a fall in demand, an increase in costs, or a need to allocate scarce resources efficiently. Here, the immediate problem is a leftward shift of the demand curve for Coffee Corner's product.
在考试中，一定要先指出经济问题。它可能是需求的下降、成本的增加，或者有效配置稀缺资源的需要。在这里，直接的问题是咖啡角产品的需求曲线向左移动。
4. Demand Analysis: What Do Consumers Want? | 需求分析：消费者想要什么？
Demand is the quantity of a good or service that consumers are willing and able to buy at different prices over a period of time. The law of demand states that, ceteris paribus, as price falls, quantity demanded rises. Before QuickBrew, we can model a simplified daily demand schedule for The Coffee Corner. Suppose at £3.00 they would sell 40 cups, at £2.50 they sell 100 cups, and at £2.00 they would sell 160 cups.
需求是指在某段时间内，消费者在不同价格水平上愿意并且能够购买的商品或服务的数量。需求定律指出，在其他条件不变的情况下，价格下降，需求量上升。在快煮出现之前，我们可以为咖啡角模拟一个简化的日需求表。假设在3.00英镑时他们会卖出40杯，2.50英镑时卖出100杯，2.00英镑时卖出160杯。
We can express this initial demand relationship as a linear equation: QD = 260 – 0P, where QD is quantity demanded and P is price in pounds. Check: when P = 2.50, QD = 260 – 80 × 2.50 = 260 – 200 = 60? That doesn't match. Let' a proper line: assume two points (P=2.50, Q=100) and (P=2.00, Q=160). Slope = ΔQ/ΔP = (160 – 100)/(2.00 – 2.50) = 60/(–0.50) = –120. So QD = a – 120P. Using (2.50, 100): 100 = a – 120 × 2.50 = a – 300, so a = 400. Demand equation: QD = 400 – 120P. At P=3.00, QD = 400 – 360 = 40. Perfect.
我们可以用线性方程表达这个初始需求关系：QD = 400 – 120P，其中QD是需求量，P是以英镑为单位的价格。检查：当P=3.00时，QD = 40；P=2.50时，QD = 100；P=2.00时，QD = 160。非常完美。
However, after QuickBrew's entry, the demand for The Coffee Corner's coffee has shifted leftwards. At the original price of £ antity demanded is now 60 cups. Assume the slope remains the same because the product hasn' -price determinant (number of substitutes) has altered. The new demand equation becomes QD' = 400 – 120P – shift. At P=2.50, QD' = 60. So 60 = 400 – 120 × 2.50 – shift = 400 – 300 – shift = 100 – shift. Hence shift = 40. New demand: QD' = 360 – 120P.
然而，在快煮进入后，咖啡角咖啡的需求向左移动了。在原价2.50英镑时，现在的日需求量为60杯。假设斜率不变，因为产品本身没变，只是非价格决定因素（替代品的数量）发生了变化。新的需求方程变为QD' = 360 – 120P。
This means that for every price, Coffee Corner now sells 40 fewer cups. The non-price determinants causing this shift include a change in the price of substitutes (QuickBrew is cheaper) and possibly a change in consumer tastes towards a new brand.
这意味着在每一个价格下，咖啡角现在都将少卖出40杯。导致这一移动的非价格决定因素包括替代品价格的变化（快煮更便宜），以及消费者可能对新品牌的偏好发生变化。
5. Supply Analysis: Costs and Production | 供给分析：成本与生产
flects the quantity a firm is willing and able to produce at each price. The Coffee Corner' ial. Fixed costs (rent, business rates) do not vary with output. Here, daily fixed cost is £80 rent. Variable costs change with quantity; for coffee, the variable cost per cup is £0.80 for ingredients plus labour. However, wages of £120 are fixed in the short run if staff work fixed shifts. So total fixed cost = £80 rent + £120 wages = £200. Average variable cost = £0.80. Total cost for Q cups = £200 + £0.80Q.
供给反映的是企业在各个价格下愿意并且能够生产的数量。咖啡角的成本至关重要。固定成本（租金、商业税）不随产量变化。这里，每日固定成本是80英镑租金。可变成本随产量变化；对于咖啡，每杯的可变成本是0.80英镑原料费加上人工。不过，如果员工按固定班次工作，120英镑工资在短期内是固定的。因此总固定成本 = 80英镑租金 + 120英镑工资 = 200英镑。平均可变成本 = 0.80英镑。Q杯的总成本 = 200 + 0.80Q。
Profit = Total Revenue – Total Cost. Total Revenue = P × Q. Before the new competition, at P=2.50 and Q=100, TR = £250. TC = £200 + 0.80 × 100 = £200 + £80 = £280. So profit = –£30? Wait, that is a loss. Let' ybe labour costs are partly variable. To keep it simple for Year 9, we can assume that the £120 wages cover necessary staff regardless of cups sold, so fixed. With 100 cups sold at £2.50, TC = 200 + 80 = 280, TR = 250, loss of £30. That could be the problem: Mia was just breaking even or making a small loss? Let's adjust: suppose rent is £50 and wages £80, making fixed costs £130. At Q=100, TC = 130 + 80 = 210, TR = 250, profit = £40. That works. We'll revise the case: rent £50, wages £80, fixed costs = £130. Variable cost per cup £0.80. So total cost = 130 + 0.80Q. We'll update the case details now.
利润 = 总收入 – 总成本。总收入 = P × Q。为了更贴近实际，我们修正案例中的成本：假设租金每天50英镑，工资80英镑，固定成本合计130英镑。每杯可变成本0.80英镑。则总成本 = 130 + 0.80Q。在价格2.50英镑、销量100杯时，总收入 = 250英镑，总成本 = 130 + 80 = 210英镑，利润 = 40英镑。这更合理。
After QuickBrew's entry, Q=60 at P=2.50. TR = £150. TC = 130 + 0.80 × 60 = 130 + 48 = £178. Profit = –£ : 2.50Q = 130 + 0.80Q → 1.70Q = 130 → Q ≈ 76.5 cups. With only 60 cups sold, Mia is below break-even.
快煮进入后，价格2.50英镑下Q=60。总收入 = 150英镑，总成本 = 130 + 48 = 178英镑，亏损28英镑。咖啡角现在处于亏损状态。这说明了覆盖平均总成本的重要性。盈亏平衡点出现在总收入等于总成本时：2.50Q = 130 + 0.80Q → Q ≈ 76.5杯。仅售出60杯，米娅处在盈亏平衡点之下。
6. Market Equilibrium and Price Determination | 市场均衡与价格决定
y demanded equals quantity supplied. Before QuickBrew, we had the demand equation QD = 400 – we approximate the supply curve as upward-sloping from the shutdown point, we can assume a simple supply function: QS = –50 + 60P (for instance). Then equilibrium: 400 – 120P = –50 + 60P → 450 = 180P → P = 2.50, Q = 100. This matches the observed data perfectly.
市场均衡发生在需求量等于供给量时。在快煮出现前，我们有需求方程QD = 400 – 120P。至于供给方面，咖啡角是一个小企业，其供给取决于在价格覆盖边际成本时愿意出售的数量。如果我们假设一条简单的供给曲线：QS = –50 + 60P，那么均衡时：400 – 120P = –50 + 60P → P = 2.50, Q = 100。这完美契合观察到的数据。
After the demand shift, new demand is QD' = 360 – 120P. If supply remains unchanged, new equilibrium: 360 – 120P = –50 + 60P → 410 = 180P → P ≈ 2.28. Quantity would be QS = –50 + 60 × 2.28 ≈ –50 + 136.8 = 86.8 cups. So the market-clearing price has fallen to about £ and quantity sold would drop to around 87 cups. However, Mia initially keeps her price at £2.50, causing a surplus of quantity supplied over quantity demanded: at £2.50, QS = 100, QD' = 60, surplus of 40. This surplus puts downward pressure on price.
需求移动后，新需求为QD' = 360 – 120P。如果供给不变，新均衡价格为约2.28英镑，均衡量约87杯。但米娅最初维持2.50英镑的价格，导致供给量（100杯）超过需求量（60杯），出现40杯的过剩。这种过剩会给价格带来下行压力。
7. Elasticity: How Responsive Are Consumers? | 弹性：消费者的反应程度？
easures the responsiveness of quantity demanded to a change in price. It is calculated as: % change in QD ÷ % P. Using the original demand curve, between P=2.50 and P=2.00, QD changes from 100 to 160. %ΔQD = (60/100) × 100 = 60%. %ΔP = (–0.50/2.50) × 100 = –20%. So PED = 60% / –20% = –3. Ignoring the sign, the demand is elastic (|PED| > 1).
需求的价格弹性（PED）衡量的是需求量对价格变化的反应程度。计算公式为：需求量的变化百分比 ÷ 价格的变化百分比。利用原需求曲线，在P=2.50和P=2.00之间，QD从100变为160。需求量变化% = (60/100)×100 = 60%，价格变化% = (–0.50/2.50)×100 = –20%。因此PED = –3。忽略符号，需求是富有弹性的（|PED| > 1）。
ic demand means that a price cut would increase total revenue. If Mia reduces her price to £ ibrium), her quantity would rise to about 87 cups. Total revenue would then be 2.28 × 87 ≈ £198, compared to £150 at £ nd also means the entire curve moved; elasticity alone cannot restore the old equilibrium.
富有弹性的需求意味着降价会增加总收入。如果米娅将价格降至2.28英镑（新均衡价格），她的销售数量将升至约87杯。总收入约为198英镑，高于150英镑。但尽管如此，她可能仍然无法覆盖总成本。这就是理解PED有助于定价决策的原因。然而，需求曲线的移动意味着整条线偏移了；仅靠弹性无法恢复到原来的均衡。
8. The Role of Competition: Market Structure | 竞争的作用：市场结构
The Coffee Corner operates in a monopolistically competitive market. There are many sellers, differentiated products (independent cafe vs. chain), and low barriers to entry. The arrival of QuickBrew illustrates how easily new firms can enter. In such a market, if firms make supernormal profits in the short run, new firms enter, shifting residual demand curves leftwards until only normal profits remain in the long run. Mia was making a profit of £40, which attracted entry.
咖啡角处于垄断竞争市场中。有许多卖家，存在产品差异（独立咖啡馆 vs. 连锁店），且进入壁垒较低。快煮的到来说明了新企业可以多么容易地进入。在这样的市场中，如果企业在短期内获得超额利润，新企业就会进入，使得剩余需求曲线向左移动，直到长期内只存在正常利润。米娅获得了40英镑的利润，这吸引了进入者。
Product differentiation is key. Mia could invest in non-price competition: loyalty cards, higher quality beans, a cozier atmosphere, or complementary goods like artisan pastries. These would increase consumer preference and shift her demand curve rightwards, or make it more inelastic, reducing the impact of competitors' price cuts.
产品差异化是关键。米娅可以投资于非价格竞争：积分卡、更高品质的咖啡豆、更舒适的氛围，或者手工糕点等互补品。这些都将增加消费者的偏好，使她的需求曲线向右移动，或者使其更缺乏弹性，从而减少竞争对手降价的影响。
9. Government Intervention: Taxes and Subsidies | 政府干预：税收与补贴
The proposed £0.15 sugar tax on sugary drinks adds an extra variable cost per affected cup. Suppose 30% of Mia's drinks contain sugar and incur the tax. The new average variable cost per cup rises from £0.80 to about £ e upwards (to the left) by the amount of the tax per unit. For a firm with the supply QS = –50 + 60P, the new supply after tax could be approximated as QS_tax = –50 + 60(P – we treat the average cost increase as a unit tax, but more precisely, the supply function' increases costs, reduces supply, and raises the equilibrium price while lowering quantity.
拟议中的每杯0.15英镑糖税增加了每杯受影响饮品的可变成本。假设米娅销售的饮料中有30%含糖并需纳税，则每杯的平均可变成本从0.80英镑上升到约0.845英镑。这使得供给曲线向上（向左）移动，移动幅度等于每单位的税额。对于供给函数QS = –50 + 60P，税后的新供给可以近似为QS_tax = –50 + 60(P – 0.045)。但九年级学生只需认识到，税收会增加成本、减少供给，并提高均衡价格同时降低均衡数量。
If Mia absorbs the tax, her profit margin shrinks further. If she passes it on to consumers, demand may fall. The government may justify the sugar tax as a means to correct a negative externality (health costs of sugar consumption) and raise revenue. In your case study answer, always consider the aims and effects of government policy: does it help or hurt the business?
如果米娅自己承担税收，她的利润空间将进一步缩小。如果她将税收转嫁给消费者，需求可能会下降。政府可能会将糖税合理化为纠正负外部性（糖消费的健康成本）并增加财政收入的手段。在你的案例分析回答中，请始终考虑政府政策的目标和效果：它对企业有利还是有弊？
10. Evaluating Business Decisions | 评估商业决策
s: lower price, introduce a loyalty scheme, or expand her product range. Lowering price to £ small loss). A loyalty card (e.g. buy 9 get 1 free) effectively reduces average price but encourages repeat purchase, potentially shifting demand rightwards and making it less elastic. Adding pastries with a higher margin could create a new revenue stream, but also incurs extra costs and risk.
米娅有三个选择：降价、推出积分卡或扩展产品种类。降价到2.28英镑可以使销量回升至87杯，但仍然亏损。积分卡（如买九送一）实际上降低了平均价格，但鼓励重复购买，可能使需求曲线向右移动并降低弹性。增加利润率更高的糕点可以创造新的收入来源，但也会带来额外成本和风险。
In evaluative questions, use 'it depends' reasoning. For example, the best strategy depends on the price sensitivity of customers, the strength of brand loyalty, and the cost structure. Short-term losses might be acceptable if they build a long-term customer base. Always relate back to the case facts: QuickBrew's deep pockets as a chain may mean a price war is unwinnable for a small independent.
在评估性问题中，要使用“视情况而定”的推理。例如，最佳策略取决于顾客的价格敏感度、品牌忠诚度的强弱以及成本结构。如果短期亏损能建立起长期的顾客群，那就可以接受。要始终联系案例事实：作为连锁店的快煮资金雄厚，这可能意味着小本独立咖啡馆打价格战是赢不了的。
11. Summary and Exam Tips | 总结与考试技巧
This case study has demonstrated how to apply demand and supply shifts, equilibrium analysis, elasticity, market structure, and government intervention to a single scenario. The key is to read the case carefully, highlight quantitative data, and identify which curve shifts and why. Use economic terminology correctly: 'leftward shift in demand', 'surplus', 'price elasticity of demand', 'monopolistic competition'.
本案例研究展示了如何将供需变动、均衡分析、弹性、市场结构和政府干预应用于一个情景。关键是仔细阅读案例，标出定量数据，并确定哪条曲线发生了变动及其原因。正确使用经济术语：“需求向左移动”、“过剩”、“需求价格弹性”、“垄断竞争”。
In the exam, structure your answers with a short introduction, organised paragraphs and a conclusion. Where appropriate, draw a quick sketch graph in the answer space with labelled axes. Even a rough diagram can gain marks. Always answer the specific question: describe, explain or discuss as required. For 'discuss', present both sides before a conclusion.
在考试中，用简短的引言、有组织的段落和结论来构建你的答案。在适当的情况下，在答题空间内快速画一张带坐标轴的草图。即使是粗略的图示也能得分。务必紧扣题目要求：按要求进行描述、解释或讨论。对于“讨论”题，要在得出结论前呈现正反两面。
12. Practice Questions | 练习题
Now test yourself. 1. Explain why the demand curve for The Coffee Corner shifted leftwards. (3 marks) 2. Calculate the daily profit or loss after QuickBrew's entry if Mia keeps the price at £2.50. (3 marks) 3. With reference to price elasticity of demand, analyse whether Mia should lower her price. (4 marks) 4. Discuss the likely impact of the sugar tax on The Coffee Corner's costs and pricing. (5 marks) 5. Evaluate which non-price strategy would be most effective for Mia to regain customers. (6 marks)
现在自我检测。1. 解释为什么咖啡角的需求曲线向左移动。（3分）2. 如果在快煮进入后米娅维持2.50英镑的价格，计算每日的利润或亏损。（3分）3. 结合需求价格弹性，分析米娅是否应该降价。（4分）4. 讨论糖税对咖啡角成本和定价可能产生的影响。（5分）5. 评估哪种非价格策略对米娅重新赢回顾客最为有效。（6分）
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