It’s an excellent time to be rich, especially in the U.S.

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Around the world, the number of millionaires and billionaires issurging right along with the value of their holdings. Even aseconomic growth has slowed, the rich have managed to gain a largerslice of the world’s wealth.

Globally, almost 18 million households control more than $1million in wealth, according to a new report from the BostonConsulting Group.

These rich folk represent just 1 percent of the world’spopulation, but they hold 45 percent of the world’s $166.5 trillionin wealth. They will control more than half the world'swealth by 2021, BCG said.

Rising inequality is of course no surprise. Reams of data haveshown that in recent decades the rich have been taking ever-largershares of wealth and income — especially in the U.S.,where corporate profits are nearing records while wages forthe workforce remain stagnant.

In fact, while global inequality is simply accelerating, inAmerica it’s gone into overdrive. The share of incomegoing to the top 1 percent in the U.S. has more than doubled in thelast 35 years, after dropping in the decades after World WarII (when the rich were taxed at high double-digit rates). Thetide shifted in the 1980s under Republican President RonaldReagan, a decade when “trickle-down economics” saw tax ratesfor the rich fall, union membership shrink, and stock marketsspike.

Now, those policies and their progeny have helped put63 percent of America’s private wealth in the hands of U.S.millionaires and billionaires, BCG said. By 2021, their shareof the nation’s wealth will rise to an estimated 70percent.

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The world’s wealth “gained momentum” last year, BCG concluded,rising 5.3 percent globally from 2015 to 2016. The firm expectsgrowth to accelerate to about 6 percent annually for the next fiveyears, in both the U.S. and globally. But a lot of that can againbe attributed to the rich. The wealth held by everyone else isjust barely growing.

Where is all this wealth coming from? The sources are slightlydifferent in the U.S. compared with the rest of the world.

Globally, about half of new wealth comes from existing financialassets — rising stock prices or yields on bonds and bank deposits —held predominately by the already well-off. The rest of the world’snew wealth comes from what BCG classifies as “new wealth creation,”from people saving money they’ve earned through labor orentrepreneurship.

In the U.S., the creation of “new” wealth is a minor factor,making up just 28 percent of the nation’s wealth increase lastyear. It’s even lower in Japan, at 21 percent. In the rest ofthe Asia Pacific region, meanwhile, two-thirds of the rise isdriven by new wealth creation.

Political changes could boost the riches of Americanmillionaires even further. After the 2016 election, U.S.stocks rose as investors hoped Republican President Donald Trumpand a Republican Congress would agree to eliminate regulationsand lower corporate tax rates. The wealthy may also get a tax cutas part of the bargain.

For example, the American Health Care Act, passed by the U.S.House of Representatives to repeal and replace Obamacare,includes the elimination of taxes paid almost exclusively by thetop 1 percent.

“No one knows” what kind of tax changes will become law, saidBCG senior partner Bruce Holley. However, “this could buoy the[growth in U.S. wealth] that we are predicting.”

Unsurprisingly, for a country where almost a quarter of incomegoes to the rich and where they hold the highest concentration ofwealth, a big chunk of the world’s richest call Americahome. Two out of five millionaires and billionaires livethere, and their ranks are growing fast. There are now about 7million Americans with more than $1 million, and BCG expects 10.4million millionaires and billionaires in the U.S. by 2021. That’san annual growth rate of 8 percent, or about 670,000 newmillionaires each year.

Millionaires are far rarer in the rest of the world than in theU.S., where 5.7 percent of all households own more than $1 millionin assets. The only countries with a higher concentration ofmillionaires are much smaller nations, such as Bahrain,Liechtenstein, and Switzerland, most with a reputations as havensfor the wealthy. China has the second most millionaires andbillionaires, at 2.1 million, though its population is fourtimes the size of America.

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