To understand what President Xi Jinping envisions in his calls for "common prosperity,” look to the pilot program underway in the wealthy province of Zhejiang — home to 65 million people and some of China’s most successful private companies.

Xi’s mounting campaign to spread the wealth has sent shock waves through the economy, triggering market sell-offs and speculation that China will reverse reforms that have lifted incomes nationally and created a class of powerful billionaires.

In fact, there is already evidence of how far Beijing intends to go. In June, the national government designated Zhejiang, China’s third-richest province, to pilot policies designed to reduce inequality. In July, it released detailed targets.