Urbanization is the new hot topic for China’s leaders, as they look for renewed sources of growth for the world’s second-biggest economy.

The choices they make have enormous consequences for everything from rebalancing China’s demand toward stronger consumption to determining the future path of energy consumption.

Few are better qualified to understand the challenges than Tom Miller, author of a new book called “China’s Urban Billion: The Story Behind the Biggest Migration in Human History.”

Mr. Miller is an 11-year veteran of China, and has trekked through 85 mainland cities in the course of his work for Hong Kong’s South China Morning Post and research firm GK Dragonomics.

China Real Time threatened to tear down his apartment unless he answered our eight questions.