Alice Han and Chris Miller's July 7, 2017 Wall Street Journal article "China's Awkward Debt Problem" is the best article I have ever seen about China's political economy in recent years. I highly recommend you read the entire article, but let me give a few teasers:

China has long relied on debt to fuel growth. The country’s debt burden expanded over 2.5 times faster than its economy in 2016, and its ratio of corporate debt to GDP is one of the highest ever seen in a big economy. ...

Why can’t China kick its debt addiction? The obstacles are political, not economic. Local governments and bosses of state-owned enterprises benefit immensely from government-subsidized loans, and these groups form the backbone of the Chinese Communist Party. ...

The most powerful business interests within the party are those that benefit most from cheap, state-funded lending, fueling China’s debt bubble. The bosses of state-owned firms are in theory subordinate to the party hierarchy. In reality, they constitute a powerful lobby, demanding cheap loans from state banks and the ability to use public assets for the private interests of the monopolies they run. ...

Provincial and local government officials are even more powerful than the bosses of state-owned firms. Real-estate development—which is no less reliant on cheap credit—has driven growth in many regions. It is also a lucrative source of corruption, as local officials sell off property to developers on the cheap in exchange for kickbacks. ...