The Trade-Weighted Effective Exchange Rate Index, a common form of the effective exchange rate index, is a multilateral exchange rate index. It is compiled as a weighted average of exchange rates of home versus foreign currencies, with the weight for eachforeign country equal to its share in trade. Depending on the purpose for which it is used, it can be export-weighted, import-weighted, or total-external trade weighted.
The trade-weighted effective exchange rate index is an economic indicator for comparing the exchange rate of a country against those of their major trading partners. By design, movements in the currencies of those trading partners with a greater share in an economy's exports and imports will have a greater effect on the effective exchange rate. In a multilateral, highly globalized, world, the effective exchange rate index is much more useful than a bilateral exchange rate, such as that between the Australian dollar and the United States dollar, for assessing changes in the competitiveness due to exchange rate movements.

The invisible balance or balance of trade on services is that part of the balance of trade that refers to services and other products that do not result in the transfer of physical objects. Examples include consulting services, shipping services, tourism, and patent license revenues. This figure is usually generated by tertiary industry. The term 'invisible balance' is especially common in the United Kingdom.
For countries that rely on service exports or on tourism, the invisible balance is particularly important. For instance the United Kingdom and Saudi Arabia receive significant international income from financial services, while Japan and Germany rely more on exports of manufactured goods.

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