股市的剧烈波动正是不可预测经济的又一反复无常表现。

The wild swings in the stock market are just another ___vagary of the unpredictable economy.

他总是心血来潮地改变主意，没人能跟上他那些古怪念头。

He changes his mind on a whim, and no one can keep up with his ___vagaries.