Inequality is world leaders’ biggest worry: WEF

The widening income gap between the world's richest and poorest is leaders' greatest concern for 2015, according to a survey published by the World Economic Forum (WEF) on Friday.

Worsening inequality jumped to first place in this year's WEF survey as the biggest risk for 2015— trumping unemployment. The global body surveyed 1,767 participants across all continents, who worked in business, academia, government and international organizations.

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"Inequality is one of the key challenges of our time," said Amina Mohammed, who works in development planning at the United Nations, in WEF's report.

"While it is true that around the world economic growth is picking up pace, deep challenges remain, including poverty, environmental degradation, persistent unemployment, political instability, violence and conflict. These problems, which are reflected in many parts of this report, are often closely related to inequality."

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Last month, Federal Reserve Chair Janet Yellen warned that inequality in the U.S. was near its highest level in a century.

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"By some estimates, income and wealth inequality are near their highest levels in the past hundred years, much higher than the average during that time span, and probably higher than for much of American history before then," Yellen said in a speech.

According to Credit Suisse's Global Wealth Report, published last month, the U.S. is the seventh most unequal country by wealth in the world. It found that Russia was the most unequal.

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Other economic woes were also flagged in the WEF's report, called Outlook on the Global Agenda 2015. In the list of trends identified by those surveyed, persistence jobless growth came second, and a lack of leadership came third.