What does this mean for the rest of the world?
The most immediate effect is that it signals to the world that Beijing thinks the Chinese economy is sputtering. The move suggests China is looking for ways to get it going again. But it also has major implications for the U.S. and other countries that trade with China because it puts their companies at a disadvantage. In the U.S., it will likely reignite criticism that Beijing keeps the currency artificially low to help its own manufacturers – a charge that could get added impetus during the presidential election campaign.
a currency devaluation helps countries sell more exports, boosting the economy. Right now the Chinese economy is in the midst of an economic slowdown and has suffered from stock market turmoil, so it can use some extra help.
In the long run, China hopes to emulate developed economies with fully flexible exchange rates. That's an essential precondition if the yuan is ever to challenge the dollar as the world's reserve currency. However, China has been moving slowly.
"It's like having your dog on a leash," Gagnon says. "Think of a flexible exchange rate as you cut the leash. China's version of it is, 'We'll let another 6 inches of leash out, but it's still on a leash.'"
So while this week's devaluation is a step toward greater flexibility, no one expects China to let go of the leash altogether. If exchange rates move too far in a direction the Chinese government doesn't like, the Chinese central bank will intervene.