Net Trade

Definition

Net trade is exports minus imports (X - M), which is a key component of aggregate demand.

A surplus, where \( X > M \), adds to aggregate demand.

A deficit, where \( X < M \), subtracts from aggregate demand.

Key Influences on Net Trade

Real Incomes

Domestic real income: If domestic real incomes rise, imports become more affordable and the trade balance worsens. If domestic real incomes fall, imports become less affordable and the trade balance improves.

Foreign real income: If foreign real incomes rise, exports become more affordable and the trade balance improves. If foreign real incomes fall, exports become less affordable and the trade balance worsens.

Exchange Rates

A depreciation of the domestic currency makes exports cheaper and imports more expensive, improving the trade balance. An appreciation of the domestic currency makes exports more expensive and imports cheaper, worsening the trade balance.

The effect of an exchange rate change depends on the price elasticity of demand for exports and imports, which is explained in Theme 4.1.8 Exchange Rates. This condition — that a depreciation improves the trade balance only if the combined elasticities of demand for exports and imports are greater than one — is known as the Marshall-Lerner condition.

Note: The effect of an exchange rate change on the trade balance is not immediate. In the short run, demand is often inelastic, so a depreciation may initially worsen the trade balance before improving it in the longer run as demand becomes more elastic. This delayed improvement is known as the J-curve effect, after the shape traced by the trade balance over time.

State of the World Economy

If the world economy is growing, demand for exports rises and the trade balance improves. If the world economy is in recession, demand for exports falls and the trade balance worsens.

The state of the world economy also affects imports. If the world economy is growing, domestic consumers may import more goods and services, worsening the trade balance.

The state of the world economy is often the most important short-run driver of the trade balance for the UK, because it is a relatively open economy with a large proportion of GDP coming from exports and imports.

Protectionism

Protectionist policies, such as tariffs, quotas, and subsidies, can reduce imports and improve the trade balance. However, protectionism can also lead to retaliation from trading partners, which can reduce exports and worsen the trade balance.

Protectionism can also reduce the efficiency of the economy and lead to higher prices for consumers, which can reduce aggregate demand and economic growth.

Non-Price Factors

Non-price factors, such as quality, branding, and innovation, can affect the competitiveness of exports and imports. If domestic firms are more competitive than foreign firms, exports will rise and the trade balance will improve. If foreign firms are more competitive than domestic firms, imports will rise and the trade balance will worsen.