Just as the global economy has all but recovered from debt-fueled crises in the United States and Europe, economists have a new worry: China. They see a lending bubble there that threatens global growth unless Beijing defuses it. That’s the view that emerges from an Associated Press survey this month of 30 economists. Still, the economists remain optimistic that Beijing’s high-stakes drive to reform its economy—the world’s second-largest—will bolster Chinese banks, ease the lending bubble and benefit U.S. exporters in the long run. […] The source of concern is a surge in lending by Chinese banks. The lending was initially...