Why do countries trade with one another?

Countries trade because no country can produce everything as cheaply or as well as others, and because resources, climate and skills differ. By specialising in the goods and services they produce relatively best and trading for the rest, countries can enjoy more output, lower prices and a wider variety of goods than if each tried to be self-sufficient. Trade is the international version of the gains from specialisation, raising total world output. The main risk is increased dependence on other countries, which can be exposed by disruptions to supply.

What is protectionism and what methods are used?

Protectionism is the use of government measures to restrict imports and protect domestic industries from foreign competition. The main methods are tariffs (taxes on imports, which raise their price), quotas (limits on the quantity of imports allowed), and subsidies to domestic producers (which lower their costs so they can undercut imports). Governments may also use regulations and standards as barriers. Although protection can shield jobs and infant industries in the short run, it raises prices for consumers, reduces efficiency, and can provoke retaliation.

What is the balance of trade?

The balance of trade is the difference between the value of a country's exports and the value of its imports of goods and services over a period. A trade surplus occurs when exports exceed imports, and a trade deficit occurs when imports exceed exports. The balance of trade is an important part of a country's balance of payments, and a healthy external position is one of the four macroeconomic aims. Exchange-rate changes and the relative competitiveness of a country's goods strongly affect the trade balance.

How do exchange-rate changes affect exports and imports?

An exchange rate is the price of one currency in terms of another. When a currency appreciates (becomes stronger), the country's exports become more expensive abroad while imports become cheaper at home, which tends to reduce exports and raise imports, worsening the trade balance but easing imported inflation. When a currency depreciates (becomes weaker), exports become cheaper abroad and imports dearer at home, which tends to raise exports and lower imports, improving the trade balance but adding to imported inflation.

What is globalisation and who gains and loses from it?

Globalisation is the growing economic integration and interdependence of countries through trade, investment, the movement of people and the spread of technology, driven by cheaper transport, better communications and the activities of multinational companies. It brings real gains: lower prices, wider choice, access to foreign investment and technology, and faster growth, especially for trading economies such as Singapore. But it also creates losers: workers in industries exposed to foreign competition, and economies vulnerable to external shocks, so a balanced answer weighs both the benefits and the costs.

SingaporeEconomics

International trade and globalisation for Singapore O-Level Economics (2286): why countries trade and specialise, protectionism and the case for free trade, the balance of trade and how exchange rates affect it, and the causes and effects of globalisation

A module overview for Singapore O-Level Economics (SEAB 2286) on international trade and globalisation: why countries specialise and trade, the gains and risks of trade, protectionism and its methods versus the case for free trade, the balance of trade and how exchange-rate changes affect exports and imports, and the causes and effects of globalisation.

Generated by Claude Opus 4.88 min readSEAB-2286Updated 2026-06-13

Reviewed by: AI editorial process; not yet individually human-reviewed

Jump to a section

Why this module matters
The gains from trade
Restricting trade, and the case against it
The exchange rate and the trade balance
A more connected world
A worked exchange-rate analysis
How this module is examined
Check your knowledge

Why this module matters

International trade is central to the syllabus, and especially to Singapore, one of the most open and trade-dependent economies in the world. This module explains why countries trade, what happens when they restrict trade, how the exchange rate shapes the trade balance, and how globalisation has tied economies together. The reasoning connects directly to earlier modules: trade is specialisation on a world scale, tariffs work through demand and supply, and the exchange rate links straight back to Singapore's monetary policy. Trade and exchange-rate questions are common in Paper 2 and reward balanced, applied evaluation.

This overview ties together the dot points below, each with its own worked answer and practice. Start with why countries trade, then layer on protection, the exchange rate and globalisation.

The gains from trade

Why countries trade explains that countries specialise in what they produce relatively best and trade for the rest, just as individuals do. The gains are lower prices, wider choice and higher total output; the main risk is greater dependence on others. For a resource-scarce economy such as Singapore, trade is not optional but essential.

Restricting trade, and the case against it

Protectionism and free trade sets out the methods of protection (tariffs, quotas and subsidies), the arguments for protecting domestic industries (jobs, infant industries, national security) and the strong case against (higher prices, lost efficiency, retaliation). A good answer weighs the short-run protection against the longer-run costs.

The exchange rate and the trade balance

The balance of trade and exchange rates defines trade surpluses and deficits and shows how an appreciation makes exports dearer and imports cheaper (worsening the trade balance but easing imported inflation), while a depreciation does the reverse. This links directly to Singapore's exchange-rate-centred monetary policy from the previous module.

A more connected world

Finally, globalisation and its effects explains the causes of globalisation (cheaper transport, technology, multinationals) and weighs its benefits (lower prices, choice, investment, growth) against its costs (job losses in exposed industries, vulnerability to external shocks).

A worked exchange-rate analysis

How a depreciation affects the trade balance

Suppose the Singapore dollar depreciates against the US dollar, moving from $\text{S\textdollar}1.35 = \text{US\textdollar}1$ to $\text{S\textdollar}1.50 = \text{US\textdollar}1$ . Trace the effect on a Singapore export priced at $\text{S\textdollar}300$ and a US import priced at $\text{US\textdollar}100$ .

step 1: find the new foreign price of the export

At the old rate, a $\text{S\textdollar}300$ export cost a US buyer $\frac{300}{1.35} \approx \text{US\textdollar}222$ . At the new, weaker rate, it costs $\frac{300}{1.50} = \text{US\textdollar}200$ . The export is now CHEAPER for foreign buyers, so demand for Singapore exports tends to rise.

step 2: find the new home price of the import

At the old rate, a $\text{US\textdollar}100$ import cost a Singapore buyer $100 \times 1.35 = \text{S\textdollar}135$ . At the new rate, it costs $100 \times 1.50 = \text{S\textdollar}150$ . The import is now DEARER at home, so demand for imports tends to fall.

step 3: state the effect on the trade balance

Cheaper exports (more sold) and dearer imports (fewer bought) together tend to RAISE export revenue and LOWER import spending, so a depreciation tends to improve the balance of trade.

\text{Depreciation} \;\Rightarrow\; X \uparrow,\; M \downarrow \;\Rightarrow\; \text{trade balance improves}

step 4: evaluate

The improvement depends on demand being responsive enough (elastic) to the price changes; if exports and imports are price-inelastic in the short run, the balance may not improve at first. A depreciation also raises the price of imported food, energy and raw materials, adding to imported inflation, which is exactly why Singapore often prefers a managed appreciation when imported inflation is the bigger threat. A balanced answer notes both the trade benefit and the inflation cost.

How this module is examined

Explain the gains from specialisation. Link trade to lower prices, wider choice and higher output, and note dependence as the main risk.
Analyse protection through price. Show how a tariff or quota raises the price or limits the quantity of imports, who gains, who loses, and the risk of retaliation.
Connect the exchange rate to trade and inflation. Trace an appreciation or depreciation through export and import prices, the trade balance, and imported inflation, using Singapore's context.

Check your knowledge

Attempt these under timed conditions, then check the model solutions.

Explain two gains a country enjoys from international trade. (4 marks)
Define a tariff and a quota. (2 marks)
State two arguments for and two against protectionism. (4 marks)
Define the balance of trade and distinguish a surplus from a deficit. (3 marks)
Explain how a depreciation of a currency affects exports and imports. (3 marks)

Solutions

Q1: Any two, explained: lower prices, because countries import goods that others produce more cheaply; wider choice, because consumers can buy goods not produced at home; higher total output, because specialisation raises efficiency; and access to resources, technology or markets a country lacks. Each follows from specialising in what a country produces relatively best.
Q2: A tariff is a tax placed on imported goods, which raises their price. A quota is a physical limit on the quantity of a good that may be imported over a period.
Q3: For: protecting jobs in domestic industries; protecting infant (new) industries until they can compete; and safeguarding national security or strategic goods. Against: it raises prices for consumers; it reduces efficiency by sheltering firms from competition; and it can provoke retaliation by trading partners, harming exports.
Q4: The balance of trade is the difference between the value of a country's exports and the value of its imports over a period. A trade surplus occurs when exports exceed imports; a trade deficit occurs when imports exceed exports.
Q5: A depreciation (a weaker currency) makes a country's exports cheaper for foreign buyers, so exports tend to rise, and makes imports more expensive at home, so imports tend to fall. The combination tends to improve the balance of trade, though it also raises the price of imported goods, adding to imported inflation.

Sources & how we know this

Singapore-Cambridge GCE O-Level Economics (Syllabus 2286) — Singapore Examinations and Assessment Board (2026)