MADRID (MarketWatch) — Indeed, the rich are getting richer. And as the notorious financier, Gordon Gekko says, in the 1980s film “Wall Street:” “Rich enough to not waste time.”

The wealthiest 85 people on the planet saw their collective net worth grow a whopping $668 million every day, between March of this year and March 2013, said Oxfam, in a report released Wednesday.

Put another way, the ultra-rich generated the equivalent of nearly a half-a-million dollars—every minute of every day, for a year.

That’s wealth even Gordon Gekko might envy.

But those ballooning riches only serve to highlight the sort of troubling income inequality illustrated by economists like Thomas Piketty, in his “Capital in the Twenty-First Century.”

Oxfam’s report on Wednesday, entitled “Evening it Up:Time to end extreme inequality,” focuses on this widening fissure. The Oxfam study offers some interesting ways to think about how much money has been accumulated by uber-wealthy Americans like Bill Gates, for example.

Gates’s estimated net worth is about $76 billion. He’s the richest man in the world, according to the most recent annual rankings from Forbes.

“If Bill Gates were to cash in all his wealth and spend $1 million every single day, it would take him 218 years to spend it all. In reality though, he would never run out of money: even a modest return of just under two percent would make him $4.2 million each day in interest alone,” said Oxfam.

It shouldn’t go unmentioned, of course, that Gates has pledged to donate the majority of his wealth to charity. See Why America’s rich are giving less of their wealth to charity.

Still, the income disparity between billionaires and those just scraping by has only expanded, over the past several decades. According to a recent study by the Stanford Center on Poverty and Inequality, reflecting household income data from 1968 to 2012 in the U.S., the gap between the wealthiest and the poorest started widening in the 1980s (pdf, pg. 31). But the trend has accelerated during the 1990s. The inequality gap became more pronounced during the recent Great Recession.

The number of billionaires in the world have more than doubled to 1,645 between 2009 and 2014. In Sub-Saharan Africa, 16 billionaires are living alongside 358 million people in dire poverty, according to an earlier Oxfam report.

“Too many children born today have their future held hostage by the low income of their parents, their gender and their race,” said Mark Goldring, Oxfam’s chief executive.

Experts have noted that income inequality has a real impact on the global economy and society as a whole.

So how do we fix it?

One of Oxfam’s suggestions has been a wealth tax. It estimates that a tax of just 1.5% on the wealth of the world’s billionaires, if implemented just after the financial crisis, would have saved 23 million lives in the poorest 49 countries, by providing them with money to invest in healthcare.

The fissure between the wealthiest of the wealthy and poorest of the poor has increased so rapidly that in 2014, a tax of 1.5% could fill the annual funding deficits needed to put every child in school, and deliver health services to the poorest countries.

Earlier this year, a report from Oxfam, showing that the wealth of those 85 richest people around the world equals the assets held by half of the world’s population, went viral. Also see ‘Rich Kids of Beverly Hills’ has a message for Davos leaders.

Maybe a billionaire tax is a plausible solution. Renowned billionaires Warren Buffett and George Soros, in the past, have called on Congress to raise estate taxes.

Economists, like Piketty, also have favored the notion of a wealth tax.

Read also: 10 things billionaires won’t tell you