The balance of trade (BoT) is the value of a country’s exports of goods minus its imports of goods over a period.
[ \text{BoT} = X_g - M_g ]
where (X_g) is goods exports and (M_g) is goods imports. A positive BoT is a trade surplus; a negative BoT is a trade deficit.
In national income accounting, the trade balance is closely related to net exports and the broader balance-of-payments system.
How It Fits Into The Balance Of Payments
The balance of trade is a major component of the current account, which is often summarized as:
[ \text{Current Account} = (X_g - M_g) + (\text{services}) + (\text{income}) + (\text{transfers}) ]
When the current account is in deficit, it must be financed by net capital inflows or by running down foreign exchange reserves. In other words, external deficits and external financing are mechanically linked.
What Moves The Balance Of Trade
Common drivers include:
- Exchange rates: depreciation tends to make exports cheaper and imports more expensive, though the effect depends on elasticities and timing.
- Domestic income and demand: a domestic boom often raises imports.
- Global demand: external growth raises export demand.
- Commodity prices and terms of trade: for commodity exporters, price swings can dominate the goods balance.
- Trade policy and non-tariff barriers: can shift volumes and composition, but may trigger retaliation or higher input costs.