It’s shaping up to be an epic battle: President Biden has vowed to raise taxes on the wealthy to fund programs benefiting those at lower income levels. “I want to change the paradigm,” Biden said in a press conference in March. Conservative advocacy groups, meanwhile, are preparing to fight any hikes. But income disparity—and debate about how to address it—is not just a U.S. phenomenon.

A report by Oxfam International found that global billionaires increased their wealth by some $3.9 trillion from the onset of the pandemic through the end of 2020, even as millions fell into poverty. And the graphics below, drawn from the World Inequality Database, show that the share of income going to the richest 10% has been rising in many large economies around the globe.

This article appears in the April/May issue of Fortune.