China has pulled hundreds of millions of people from poverty, supercharged its economy and burnished the pride of a nation that stood weak and isolated only decades ago. But swelling levels of debt, bloated state companies and an overall aversion to market forces are swamping the world’s second-largest economy, threatening to derail China’s ascent to the ranks of rich countries. As Beijing battles another bout of stock-market turmoil —and global markets shudder in response —the risks of doing nothing about these deep-seated problems are rising, economists said. Without a change in course, they said, China faces a period of low growth , crimped worker productivity and stagnating household wealth. It’s a condition known as “the middle-income trap.” “The era of easy growth is over,” said Victor Shih, professor at the University of California-San Diego. “It’s increasingly about difficult choices.” Some economists don’t rule out an abrupt drop in growth […]