2019 was the year many asked the question: Should billionaires exist?
Income inequality in the United States is at its highest level in at least 50 years, according to one measurement from the government's Census Bureau. In January, Oxfam reported that the world's wealthiest 26 individuals, as of 2018, had the same amount of wealth as the poorest half of the population.
There were 2,153 billionaires as of March, with the ultra-rich worth $8.7 trillion, according to Forbes.
It's against this backdrop that a number of billionaires addressed the issue of inequality, some with progressive agendas to improve American capitalism, the same system that allowed them to become some of the world's wealthiest people.
Net worth: $108.1 billion, according to Forbes
What he said: "There's no free lunch here. You'd have to collect more money," Microsoft co-founder Bill Gates told CNN's Fareed Zakaria in February, about raising taxes. "As you go about doing this additional collection, of course you want to be progressive. You want the portion that comes from the top 1% or top 20% to be much higher," Gates said.
Even as he supports higher taxes, Gates believes in the fundamentals of capitalism: "You have market-based pricing. You let people create new companies very easily," Gates told Zakaria. "If you think there's a lot of competition someplace, you come in and intervene on that."
That system should not be overturned, he said.
"Flirting with radical change, dramatic change, how we run these systems, I personally — my vote will be not to make a radical change," he said.
"Now you can say I'm biased because this system has worked very well for me, and I feel — I plead guilty to that. But as I look overall at the capitalist economies, there are a lot of good things ... and I think you can tune the tax parameters and get way more equity and get some additional government services and still be in the same basic framework," he said.
Net worth: $18.7 billion, according to Forbes
What he said: "Capitalism needs to be reformed. It doesn't need to be abandoned. So like anything, like a car, like anything, a plane, a school system, anything, it needs to be reformed in order to work better," Ray Dalio, founder of the world's largest and most profitable hedge fund, said in July on CBS' "60 Minutes," explaining that the U.S. economy is not "redistributing opportunity."
Dalio went as far as to say, "I think the American dream is lost."
The current situation is not sustainable, according to Dalio: "We're at a juncture. We can do it together, or we will do it in conflict, that there will be a conflict between the rich and the poor," Dalio said.
In November on LinkedIn, Dalio spoke out again, saying, "The world has gone mad and the system is broken. ... Because the 'trickle-down' process of having money at the top trickle down to workers and others by improving their earnings and creditworthiness is not working, the system of making capitalism work well for most people is broken."
Net worth: $6.9 billion, according to Forbes
What he said: "Capitalism, I acknowledge, has been good to me," Mark Benioff, the co-founder of Salesforce, wrote in The New York Times in November. "But capitalism as it has been practiced in recent decades — with its obsession on maximizing profits for shareholders — has also led to horrifying inequality."
Benioff's op-ed in the Times calls for a "new capitalism," which among other things would include higher taxes on America's richest, including himself. "Nationally, increasing taxes on high-income individuals like myself would help generate the trillions of dollars that we desperately need to improve education and health care and fight climate change," he wrote.
Net worth: $75.7 billion, according to Forbes
What he said: "I don't know if I have an exact threshold on what amount of money someone should have, but at some level no one deserves to have that much money," Facebook founder Mark Zuckerberg said of billionaires during a live-streamed question and answer session in October. "I think if you do something that is good, you get rewarded, but I do think some of the wealth that can be accumulated is unreasonable."
He also said extreme wealth at the hands of a few, if they choose to spend it to better society, might be better than the alternative of the government controlling all of the wealth. "At some level it is not fair, but it may be optimal," he said, "or better than the alternative. The alternative would be the government chooses all of the funding for all of the stuff."
(Some experts have argued that even through philanthropy, the rich have a disproportionate or unfair influence on society, and Rob Reich, a political theorist at Stanford and author of "Just Giving: Why Philanthropy Is Failing Democracy and How It Can Do Better," even called it "plutocratic.")
Net worth: $4.1 billion, according to Forbes
What he said: "The biggest issue for entrepreneurs, for capitalists, for those of us who are successful is, if someone is only going to be paid by the hour ... they're always going to fall behind," Cuban told Recode Decode with Kara Swisher at the 2019 SALT Conference in Las Vegas in June. "And income distribution is … [the] disparity is going to get wider and wider."
So, said Cuban, "We as entrepreneurs have got to make a point to give stock to everybody that works for us. Period. End of story. No exceptions, because that's the only way people are going to get any type of equity appreciation."
"Capitalism isn't bad. It's when capitalists don't pay attention" that "bad things can happen," Cuban said. "Our country is a lot like running a business ... you can't just look at the short term in the immediate aspect, you've got to look at the long term."
Net worth: $88.8 billion, according to Forbes
What he said: "I'm a card-carrying capitalist," Buffett told Andrew Ross Sorkin in May at the annual meeting for the investing firm which he heads, Berkshire Hathaway. The Omaha weekend event is called "Woodstock for Capitalists," Sorkin notes in his column in the New York Times.
"I believe we wouldn't be sitting here except for the market system," he told Sorkin. "I don't think the country will go into socialism in 2020 or 2040 or 2060."
Buffett supports capitalism because the market economy is productive and generates wealth.
″[T]he most important single thing is to have more 'golden eggs' to distribute around," Buffett said in February in an interview with CNBC's Becky Quick. "So I don't wanna do anything to the goose that lays the golden eggs. And we've had the goose that lays more and more golden eggs over the years, unbelievable in this country."
"So we've got something that works in terms of the market system in terms of turning out lots of goods and services people want," Buffett said.
That being said, Buffett also says the United States ought to use the wealth generated by that "golden goose" to take care of those who are otherwise good people but don't have skills that the market economy values.
"A rich family can handle if they've got six children and one of them isn't as good in the market ... is just good in every other personal quality. They take care of him," Buffett told Quick. "So we can take care of people and we should. But we shouldn't screw up the market system."
Net worth: $1.7 billion, according to Forbes
What he said: Socialism is not a viable solution, said Dimon in his annual letter to shareholders published in April.
"When governments control companies, economic assets (companies, lenders and so on) over time are used to further political interests – leading to inefficient companies and markets, enormous favoritism and corruption," Dimon wrote in the letter, which was released with the bank's 2018 annual report.
"Socialism inevitably produces stagnation, corruption and often worse – such as authoritarian government officials who often have an increasing ability to interfere with both the economy and individual lives – which they frequently do to maintain power. This would be as much a disaster for our country as it has been in the other places it's been tried," he added.
The CEO of JPMorgan Chase was unequivocal in his support of capitalism as the best, yet still imperfect, economic system.
"There is no question that capitalism has been the most successful economic system the world has ever seen. It has helped lift billions of people out of poverty, and it has helped enhance the wealth, health and education of people around the world. Capitalism enables competition, innovation and choice," Dimon wrote.
That being said, like Buffett, Dimon also said the governments of capitalistic economies ought to support those who are struggle.
"This is not to say that capitalism does not have flaws, that it isn't leaving people behind and that it shouldn't be improved. It's essential to have a strong social safety net – and all countries should be striving for continuous improvement in regulations as well as social and welfare conditions," Dimon wrote.
Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank."
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