They claim a relationship between the rotation and the magnetic polarity of Earth, which does change irregularly, with a magnetic reversal taking place every 400,000 years on average.

他们声称地球的自转和地球的磁极的关系不稳定，预示着平均每40万年就有一次的磁极颠倒。

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But the Internet is unlikely to make all prices more flexible, especially because it may often be more efficient for prices to change irregularly.

ECONOMIST: Is this the end of sticky prices?