Beijing signaled with its currency devaluation that the domestic economic slowdown it has failed to reverse is no longer a problem confined within China’s borders. It is now the world’s problem, too. Chinese officials have cut interest rates four times in the past 12 months, increased the amount of money banks can lend out and pumped funds into the stock market—measures meant to boost domestic demand in the world’s second-largest economy. By devaluing the yuan, Chinese authorities are turning to a controversial growth-boosting tactic whose effects by their nature reverberate far and wide. A cheaper yuan could help boost Chinese exports . It also might complicate the Federal Reserve’s decision about when to start raising U.S. interest rates. It will pressure China’s direct trade rivals, such as South Korea and Japan, to follow suit and let their own currencies fall. It raises risks of market volatility in other emerging […]