China has seen its foreign reserves depleted for months, but economists don’t agree about why: Is it because Chinese people are buying offshore assets, such as real estate? Because Chinese companies are paying down their foreign debt? Or both? Or is it because of something more to do with complex bets on foreign exchange movements? What explains why China’s foreign exchange reserves fell this spring to their lowest level since December 2011? And what long-term effects might this have on the U.S.-China relationship and China’s trade with the world?