A good example would be the current economical issue that the world is facing now, especially the US. Given that the US is in a financial turmoil, the purchasing power of both companies and consumers are affected tremendously, such that no one would want to spend unnecessarily, but to save more money. This thus impacts on the economical factor of the country as their people are not spending, due to high inflation as well, hence the GDP of the country defluctuates and so does the exchange rate of the US dollar.
Keats