The long-standing economic rivalry between China's major provinces, Guangdong and Jiangsu, is intensifying. Latest data shows the gap between the two economic heavyweights is narrowing, suggesting a shift in regional economic power within China.

The long-standing rivalry between China’s two largest economic heavyweights – with each boasting a gross domestic product comparable to Group of Seven members Italy and Canada – reflects the regional dynamism and shifting economic gravity within the world’s second-biggest economy. Jiangsu has been threatening to end Guangdong’s uninterrupted reign as China’s largest provincial economy since the late 1980s, and the latest economic data reveals the gap between the two narrowed further in the first...