By now you’ve probably heard, China’s economy is not doing so well.

The country’s once-booming real estate sector is stalled. China has slipped into deflation. Foreign direct investment is down. So are exports. Youth unemployment reached a record high of more than 20 percent in June. And this is just what we know. After all, China has slowly stopped releasing lots of public economic data, making it hard to get a complete picture.

What we do know is that the story of China’s unimpeded economic rise is turning out to be a bit more complicated — and it may have been a long time coming, with or without China’s very strict Covid-19 pandemic policies. All of this could have profound economic, political, and social fallout for Beijing, and the rest of the world.

Before getting there, it’s worth trying to figure out the basics on why China’s economy is struggling right now. To do that, Vox called up Stephen Morgan, a professor emeritus of Chinese Economic History at the University of Nottingham, who wrote a book on the Chinese economy.