Amazon has kept prices low in order to boost demand for its Kindle, which dominates the e-reader market but faces stiff competition from Sony and others.
Farmers were frequently not paid the full world price for their crops, because governments were determined to keep local prices low in order to relieve hard-pressed consumers.
China is playing its own currency game, trying to keep the yuan low in order to protect internal interests, but still it is having to react to the American moves.