Oligopoly: Key Exam Points for IGCSE OCR Economics | IGCSE OCR 经济：寡头 考点精讲

📚 Oligopoly: Key Exam Points for IGCSE OCR Economics | IGCSE OCR 经济：寡头 考点精讲

Oligopoly is a fascinating and highly examinable market structure in IGCSE OCR Economics. Understanding its characteristics, interdependence, and strategic behaviour is crucial. This article distils the key points you need to master, from kinked demand curves to game theory.

寡头垄断是IGCSE OCR经济中既有趣又极容易考查的市场结构。理解其特征、相互依存关系和策略行为至关重要。本文提炼了你需要掌握的核心考点，从弯折需求曲线到博弈论。

1. What is Oligopoly? | 什么是寡头垄断？

An oligopoly is a market structure where a few large firms dominate. These firms can sell identical products (e.g. petrol) or differentiated products (e.g. smartphones). The high level of concentration gives each firm significant market power, but they must also consider the reactions of rivals when making decisions.

寡头垄断是一种由少数大企业主导的市场结构。这些企业可以销售同质产品（如汽油）或差异化产品（如智能手机）。高度集中赋予了每家企业显著的市场力量，但它们在决策时也必须考虑竞争对手的反应。

Typical examples include the UK supermarket industry (dominated by Tesco, Sainsbury’s, Asda, and Morrisons) and the global soft drinks market (Coca-Cola and PepsiCo).

典型例子包括英国超市行业（由Tesco、Sainsbury’s、Asda和Morrisons主导）和全球软饮料市场（可口可乐和百事可乐）。

2. Characteristics of Oligopoly | 寡头垄断的特征

The distinguishing features of an oligopolistic market are:

寡头市场的显著特征包括：

1. Few dominant firms: A small number of large sellers account for the majority of the industry’s output.

1. 少数主导企业：少数大型卖方占据了行业产出的绝大部分。

2. High barriers to entry: Factors like high start-up costs, economies of scale, brand loyalty, and legal patents prevent new competitors from easily entering the market.

2. 高进入壁垒：高昂的启动成本、规模经济、品牌忠诚度以及法律专利等因素阻止新竞争者轻易进入市场。

3. Interdependence: Each firm’s strategy directly affects others, so they must anticipate rivals’ reactions.

3. 相互依存：每家企业的策略直接影响其他企业，因此它们必须预见竞争对手的反应。

4. Product differentiation: Products may be identical (e.g. steel) or differentiated through branding, quality, and design (e.g. cars).

4. 产品差异化：产品可以是同质的（如钢铁）或通过品牌、质量和设计进行差异化（如汽车）。

5. Non-price competition: Due to price rigidity, firms compete using advertising, loyalty cards, after-sales service, and product innovation.

5. 非价格竞争：由于价格刚性，企业通过广告、会员卡、售后服务和产品创新来进行竞争。

3. Concentration Ratios | 集中度比率

Economists use concentration ratios to measure the degree of market power. The most common is the 5-firm concentration ratio (CR5), which adds up the market share of the five largest firms. A market with a CR5 above 60% is typically considered an oligopoly.

经济学家使用集中度比率来衡量市场力量的程度。最常见的是5企业集中度比率（CR5），即将最大五家企业的市场份额相加。CR5超过60%的市场通常被认为是寡头垄断。

The table below shows some hypothetical CR5 values:

下表展示了一些假设的CR5数值：