Just eight super-rich men hold the same amount of wealth as the poorest half of the world’s population, according to an analysis from the charity Oxfam released Sunday night.?

Six of these billionaires, from Forbes’ list of the world’s richest people, are American entrepreneurs: Microsoft co-founder Bill Gates, Berkshire Hathaway chairman and CEO Warren Buffett, Amazon founder and CEO Jeff Bezos, Oracle co-founder Larry Ellison, former New York Mayor Michael Bloomberg and Facebook founder and CEO Mark Zuckerberg. Rounding out the list are Carlos Slim, the Mexican tycoon, and Amancio Ortega, the Spanish founder of a retail conglomerate that includes clothing chain Zara. Together their net wealth ― assets minus debts ― amounts to $426 billion.

We cannot name the bottom half of humanity, more than 3.6 billion people, with that kind of precision, but they mostly live in the developing world.

Worsening inequality threatens to upend the very fabric that’s held democracies together in the post-World War II global order. In the United States, the widening gulf between the rich and everyone else helped propel Donald Trump into office. Overseas, the trend is credited with sparking Brexit, the U.K.’s vote to leave the European Union.

In 2016, the richest 1 percent of the world held slightly more than half of the wealth of the entire planet, Oxfam notes. And the 1,810 billionaires on Forbes’s list ― 89 percent male ― hold $6.5 trillion, as much wealth as 70 percent of humanity.

Rising inequality causes more than a sense of moral outrage and the election of reality TV stars. There’s a wide body of research that shows inequality adversely affects the health of those at the bottom, raising the risk of cardiovascular disease, increasing suicide rates and shortening lifespans. Some attribute the rise in the death rate of white people and the heroin epidemic to inequality.