In fact, may of the movements in both exports-sales and import-sales ratios are short term in nature. Short term influences include (for example) cyclical factors operating at the macro-level and movements in the exchange rate.

没有看明白这句话。不知道cyclical factors指的是什么？是否是business cycle？也不是很清楚cyclical factors与exchange rate的关系。

自己看了一些资料，猜想如果是指business cycle的因素，大约是因为经济周期阶段诸如萧条，危机等因素造成国际收支不平衡，而且国际收支平衡表里面，进出口贸易又是很重要的项目，这样连带着也波及到了汇率。

请高人指点，谢谢。