While oil-exporting countries receive revenues in dollars (or their euro equivalent), they use different currencies to import goods and services from various countries. Any change in the exchange rate of the dollar affects the purchasing power of these countries, and therefore their real income.
在石油出口国以美元（或他们的欧元等价物）取得收入的同时，他们用不同的货币从许多国家进口货物和服务。美元汇率的任何变动都会影响这些国家的购买力，继而影响他们的真正收入。