American's millionaires control about two-thirds of the nation's wealth, a far greater concentration of wealth than in any other country in the world.
About 66% of U.S. wealth in 2015 was held by households worth $1 million or more, according to a new report on global wealth by the Boston Consulting Group. That compares to 46% of the wealth worldwide that's held by millionaires. Wealth is less concentrated in the hands of millionaires in other developed economies around the globe.
In Western Europe, millionaires control 31% of the wealth, while in Japan the figure is 22%. Elsewhere in the Asia-Pacific region, 44% of the wealth is held by millionaires.
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Eastern Europe, the Middle East and Africa are the only other regions besides North America where more than half the wealth is controlled by millionaires -- averaging about 55% percent.
And the concentration of wealth is expected to keep increasing. Boston Consulting Group projects that 71% of U.S. wealth will be in the hands of millionaires by 2020.
Anna Zakrzewski, a Boston Consulting Group partner and coauthor of the report, says that the millionaires are accumulating more wealth worldwide because of investment gains, which outpace growth from wages and other income.
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"They're able to invest into asset classes with higher returns, even if they're a bit riskier," she said.
The number of millionaires worldwide grew by 1.1 million, or 6%, last year to 18.5 million, and about half that growth was in Asia-Pacific region, including China. Western Europe was responsible for about a third of the growth. But the United States still had by far the most millionaires, with 8 million households crossing that mark, compared to only 2 million in China and 1 million in Japan.
