A new report from Oxfam says that global inequality of individual wealth has skyrocketed in recent years. Here’s one statistic: The world’s count of billionaires has doubled since the financial crisis.

Of the 10 richest people in the world, seven are Americans. Oxfam also found a strong gender gap, with only three women on the list of the world’s 30 richest people. The report’s list of social problems tied to economic inequality is exhaustive: health, education, income opportunity, the gender wage gap, poverty, climate change, and violence.

"The gap between the rich and the poor is spiraling out of control. In fact, the number of billionaires in the world has more than doubled since the financial crisis," said Raymond C. Offenheiser, president of Oxfam America, in a press release. "Far from being a driver of economic growth, extreme inequality is a barrier to prosperity for most people on the planet. It hinders economic growth, corrupts politics, stifles opportunity and fuels instability."

What’s led to such extreme concentrations of wealth? The wealth of the world’s 1,646 billionaires combined is $5.4 trillion—a third of the U.S. yearly GDP—while there 870 million people living in extreme poverty. Oxfam cites two reasons: laissez faire policies and the ability of the wealthy to hold power. Oxfam argues that taxes are being kept low by the economic elite buying political clout with their money.