📚 Protectionism | 保护主义
Protectionism refers to government policies that restrict international trade in order to shield domestic industries from foreign competition. For Cambridge A-Level Economics, you need to analyse the main instruments of protection, their welfare effects on consumers, producers and government, and the arguments for and against their use.
保护主义是指政府为保护本国产业免受外国竞争而限制国际贸易的政策。在剑桥 A-Level 经济学中，你需要分析主要的保护工具、它们对消费者、生产者和政府的福利效应，以及支持和反对使用这些政策的理由。
1. What is Protectionism? | 什么是保护主义？
Protectionism is any government action that gives domestic producers an artificial advantage over foreign competitors. It is the opposite of free trade, where goods and services move across borders without government restrictions.
保护主义是指政府给予国内生产者相对于外国竞争者人为优势的任何行为。它与自由贸易相反，自由贸易下商品和服务在没有政府限制的情况下跨境流动。
The main instruments of protection include tariffs, import quotas, subsidies to domestic firms, and non-tariff barriers such as product standards and administrative regulations.
主要的保护工具包括关税、进口配额、对国内企业的补贴，以及非关税壁垒，如产品标准和行政法规。
Protectionism usually raises the domestic price of imported goods, reduces the quantity of imports, and transfers income from consumers to domestic producers and the government.
保护主义通常会提高进口商品的国内价格，减少进口数量，并将收入从消费者转移给国内生产者和政府。
2. Tariffs | 关税
A tariff is a tax imposed on imported goods. It can be specific, meaning a fixed amount per unit imported, or ad valorem, meaning a percentage of the import price.
关税是对进口商品征收的税。它可以是从量税，即每单位进口征收固定金额，也可以是从价税，即按进口价格的一定百分比征收。
When a tariff is imposed, the domestic price rises from the world price Pw to Pw + t, where t is the tariff per unit. Domestic producers can now sell more at the higher price, while domestic consumers buy less.
征收关税后，国内价格从世界价格 Pw 上升到 Pw + t，其中 t 是每单位关税。国内生产者现在可以以更高的价格卖出更多产品，而国内消费者购买量减少。
The tariff creates government revenue equal to the tariff rate multiplied by the new quantity of imports. It also creates a deadweight loss because the economy produces goods at a higher opportunity cost than foreign suppliers would have faced.
关税创造了政府收入，等于关税率乘以新的进口数量。同时，由于本国生产商品的机会成本高于外国供应商本应承担的成本，关税还造成了无谓损失。
Government revenue = tariff per unit × quantity of imports after tariff
3. Import Quotas | 进口配额
An import quota is a physical limit on the quantity of a good that can be imported over a given period. Once the quota is reached, no further imports are allowed.
进口配额是对某一商品在一定时期内可进口数量的实物限制。一旦达到配额，就不再允许进一步进口。
Like a tariff, a quota raises the domestic price and reduces the quantity consumed. However, the government does not automatically collect revenue unless it sells import licences. The difference between the world price and the higher domestic price becomes quota rent, which may go to importers or foreign exporters.
与关税类似，配额会提高国内价格并减少消费量。然而，除非政府出售进口许可证，否则政府不会自动获得收入。世界价格与较高国内价格之间的差额成为配额租金，可能归进口商或外国出口商所有。
| Feature 特征 | Tariff 关税 | Quota 配额 |
|---|---|---|
| Price effect 价格效应 | Raises domestic price 提高国内价格 | Raises domestic price 提高国内价格 |
| Government revenue 政府收入 | Yes, from tax 有，来自税收 | Only if licences sold 仅在出售许可证时有 |
| Flexibility 灵活性 | Adjustable by price 可随价格调整 | Fixed quantity 数量固定 |
Because quotas are less transparent and can generate rent-seeking, many economists prefer tariffs as the less distorting form of protection.
由于配额较不透明且可能引发寻租行为，许多经济学家认为关税是扭曲较小的保护形式。
4. Subsidies to Domestic Producers | 对国内生产者的补贴
A subsidy is a payment from the government to domestic producers, often per unit of output. It lowers their production costs and shifts the domestic supply curve to the right.
补贴是政府向国内生产者支付的款项，通常按单位产量计算。它降低了生产成本，并使国内供给曲线向右移动。
With a subsidy, domestic output increases and imports fall, but the domestic consumer price can remain close to the world price. The main cost is borne by taxpayers, not consumers.
有了补贴，国内产量增加，进口减少，但国内消费者价格可以保持在接近世界价格的水平。主要成本由纳税人承担，而不是消费者承担。
Compared with a tariff or quota, a production subsidy creates a smaller loss in consumer welfare. However, it still misallocates resources by encouraging production that may not be efficient by world standards.
与关税或配额相比，生产补贴对消费者福利造成的损失较小。但它仍然通过鼓励按世界标准可能并不高效的生产来造成资源错配。
Subsidy cost to government = subsidy per unit × domestic output after subsidy
5. Non-Tariff Barriers | 非关税壁垒
Non-tariff barriers are regulations or administrative practices that restrict imports without using a direct tax or quota. They include product standards, labelling requirements, customs delays, licensing rules, and voluntary export restraints.
非关税壁垒是指在不使用直接税收或配额的情况下限制进口的法规或行政做法。它们包括产品标准、标签要求、海关延误、许可证规则以及自愿出口限制。
These barriers are often justified on health, safety or environmental grounds, but they can be used as hidden protectionism. Because they are harder to measure, they can be more damaging than transparent tariffs.
这些壁垒通常以健康、安全或环境为由，但它们可能被用作隐蔽的保护主义。由于它们更难衡量，可能比透明的关税更具破坏性。
For example, a country may require imported cars to pass costly emissions tests that domestic producers have already designed their vehicles to meet.
例如，一个国家可能要求进口汽车通过昂贵的排放测试，而国内生产商已经将其车辆设计为符合这些测试。
6. Arguments for Protectionism | 支持保护主义的理由
The infant industry argument says that new domestic industries need temporary protection from established foreign rivals until they can achieve economies of scale and lower average costs.
幼稚产业论认为，新兴国内产业需要暂时免受成熟外国竞争对手的保护，直到它们能够实现规模经济并降低平均成本。
Strategic trade policy suggests that governments can use protection to help domestic firms gain a competitive advantage in industries with large economies of scale, such as aircraft manufacturing.
战略性贸易政策认为，政府可以利用保护来帮助国内企业在具有大规模经济的行业中获得竞争优势，例如飞机制造业。
Protection can also preserve jobs in import-competing industries, protect national security by keeping essential goods produced domestically, and prevent dumping of cheap foreign goods that could destroy domestic firms.
保护还可以保住进口竞争行业的就业，通过在国内生产必需品来保护国家安全，并防止廉价外国商品的倾销破坏国内企业。
Protection may raise government revenue, reduce a balance of payments deficit, and help diversify an economy away from over-dependence on one export commodity.
保护可以增加政府收入，减少国际收支逆差，并帮助经济实现多元化，摆脱对一种出口商品的过度依赖。
7. Arguments Against Protectionism | 反对保护主义的理由
Protectionism raises consumer prices and reduces the real purchasing power of households. It also narrows consumer choice and lowers the quality of goods available.
保护主义提高了消费者价格，降低了家庭的实际购买力。它还缩小了消费者选择范围，降低了可获得商品的质量。
It misallocates resources by shifting production away from industries where the country has a comparative advantage towards protected industries that may be inefficient.
它将生产从该国具有比较优势的行业转移到可能效率低下的受保护行业，从而造成资源错配。
Protection can provoke retaliation from trading partners, leading to a trade war in which all countries lose export markets and economic growth slows.
保护可能引发贸易伙伴的报复，导致贸易战，使所有国家失去出口市场，经济增长放缓。
It also encourages rent-seeking behaviour, where firms spend resources lobbying for protection rather than improving productivity and innovation.
它还鼓励寻租行为，即企业将资源用于游说获取保护，而不是提高生产率和创新。
8. Welfare Effects of a Tariff | 关税的福利效应
When a tariff is imposed, the consumer surplus falls because consumers pay a higher price and buy fewer units. The producer surplus rises because domestic firms sell more at a higher price.
征收关税后，消费者剩余减少，因为消费者支付更高价格并购买更少单位。生产者剩余增加，因为国内企业以更高价格销售更多产品。
The government gains tariff revenue, but this is not enough to offset the total loss to consumers. The net welfare loss to society is shown by the two deadweight loss triangles.
政府获得关税收入，但这不足以弥补消费者的总损失。社会的净福利损失由两个无谓损失三角形表示。
One triangle is the production distortion loss: domestic producers now make units that could have been imported more cheaply. The other triangle is the consumption distortion loss: consumers value some units more than the world price but less than the tariff-inclusive price, so they stop buying them.
一个三角形是生产扭曲损失：国内生产者现在生产的单位本可以更便宜地进口。另一个三角形是消费扭曲损失：消费者对某些单位的估值高于世界价格但低于含税价格，因此他们停止购买这些单位。
Deadweight loss = ½ × tariff × reduction in imports
The larger the tariff and the more elastic the domestic demand and supply, the greater the deadweight loss.
关税越大，国内需求和供给弹性越大，无谓损失就越大。
9. Protectionism and Comparative Advantage | 保护主义与比较优势
The principle of comparative advantage states that countries should specialise in producing goods for which they have the lowest opportunity cost, and trade for other goods.
比较优势原理指出，各国应专门生产其机会成本最低的商品，并通过贸易获取其他商品。
Protectionism prevents specialisation according to comparative advantage. It forces resources into industries where the domestic opportunity cost is higher than the world opportunity cost, reducing global and domestic efficiency.
保护主义阻碍了按照比较优势进行的专业化。它将资源引入国内机会成本高于世界机会成本的行业，降低了全球和国内的效率。
In the long run, protection can slow down productivity growth because sheltered industries face less competitive pressure to innovate and reduce costs.
从长期来看，保护可能减缓生产率增长，因为受庇护的行业面临较少的竞争压力来创新和降低成本。
10. Evaluating Protectionist Policies | 对保护主义政策的评估
Whether protectionism is justified depends on the time horizon. Short-term employment protection may come at the cost of long-term efficiency and higher consumer prices.
保护主义是否合理取决于时间范围。短期就业保护可能以长期效率和更高的消费者价格为代价。
The size of the domestic economy matters. A large country may be able to improve its terms of trade with a tariff, while a small country cannot influence world prices and mainly harms itself.
国内经济规模很重要。一个大国也许能够通过关税改善其贸易条件，而小国无法影响世界价格，主要伤害的是自己。
The effective rate of protection measures the protection given to value added in an industry, not just the nominal tariff on the final good. If tariffs on imported inputs are low but tariffs on the final good are high, effective protection can be much larger than the nominal rate.
有效保护率衡量的是对某行业增加值的保护，而不仅仅是对最终商品的名义关税。如果进口投入品的关税低而最终商品的关税高，有效保护可能远大于名义税率。
International bodies such as the World Trade Organization aim to reduce protectionism through negotiated trade liberalisation, but many exceptions remain for developing countries, regional trade blocs and national security.
世界贸易组织等国际机构旨在通过谈判贸易自由化来减少保护主义，但对发展中国家、区域贸易集团和国家安全仍有许多例外。
In exam answers, you should always consider both the theoretical welfare loss and the possible strategic, social or political justifications before reaching a reasoned conclusion.
在考试答案中，你应始终在做出合理结论之前，既考虑理论上的福利损失，也考虑可能的战略、社会或政治理由。
Published by TutorHao | Economics Revision Series | aleveler.com
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