She found that six behaviours, which she called “wealth factors”, are related to net-worth potential, regardless of age or income. One of those is frugality – a commitment to saving, spending less, and sticking to a budget.

That is not surprising when you consider the habits of some of the richest people: Warren Buffett is notoriously frugal, and Richard Branson has previously said that displays of wealth embarrass him. The same extends to some A-list celebrities who rake in millions for their movies and TV appearances.

One of those behaviours, frugality, came up several times during the research – many of the millionaires she interviewed stressed the freedom that comes with spending below their means.

“Spending above your means, spending instead of saving for retirement, spending in anticipation of becoming wealthy makes you a slave to the pay cheque, even with a stellar level of income,” she wrote.

Several of the best-known millionaires and billionaires built wealth by living frugally – a habit they continue after becoming rich.

Consider Warren Buffett, who is worth US$82.8 billion and is the third-richest person in the world. Not one for lavish purchases, he spends relatively little money.

He previously told CNBC and Yahoo Finance’s Off the Cuff that he has “never had any great desire to have multiple houses and all kinds of things and multiple cars”.

He still lives in the modest Omaha, Nebraska, home he bought for US$31,500 in 1958. Adjusted for inflation, it is now worth about US$276,700.

He drives a relatively modest car – a 2014 Cadillac XTS, which had a manufacturer’s suggested retail price of US$44,600.

And instead of buying a smartphone, he uses a flip phone.

Buffett also pays only US$18 for a haircut. Plus he doesn’t pay much for food – he spends no more than US$3.17 on his daily McDonald’s breakfast and gets dinner at the modest Gorat’s steak house, where the menu items range from US$3 to US$41.

Then there's “Canada’s Warren Buffett”, the billionaire Jim Pattison, who earned his nickname from his own relatively frugal lifestyle. Pattison is worth US$6.57 billion …

… but, like Buffett, he keeps his wheels modest, driving a Dodge Ram 1500 Laramie truck around his hometown. The pricing for the 2019 model ranges from US$31,695 to US$56,495.

His frugality partly stems from his upbringing: Pattison was born during the Great Depression and grew up poor, wearing hand-me-downs and living in “Vancouver’s gritty east side”.

“Most of the time, I didn't have the money to buy anything that was any good, so I had to buy stuff that nobody wanted”, Pattison told Bloomberg.

The billionaire Richard Branson – who is now worth US$5.28 billion – also has modest roots. He is frugal when it comes to luxury items, largely because he grew up in a middle-class family.

“The idea of having a possession that is there just as pure luxury, and is not actually paying its bills is something which I’d be embarrassed about,” he previously told The Guardian.

You wouldn’t find a lot of expensive artwork hanging in any of his homes – he prefers to buy watercolours at reasonable prices. He also doesn’t spend much on clothes.

For Branson, the biggest luxury isn't money: “If we’re talking about personal luxuries – and the luxury of being your own boss – the biggest reward is the amount of time one can find for family and friends.”

Like Pattison and Branson, Charlie Ergen’s frugal habits at work and home also take root in the way he was brought up. Ergen stepped down as CEO of Dish Network in December 2017 and has a net worth of US$11 billion.

“My mum grew up in the Depression,” he told the Financial Times. “I don't have a mahogany desk.”

Every day, he brings his lunch, which consists of a sandwich and Gatorade, to work in a brown bag.

Despite her US$4.59 billion net worth, Judy Faulkner, the founder of Epic Systems, also resists the lavish life: “I never had any personal desire to be a wealthy billionaire living lavishly,” she wrote.

She reportedly has owned only two cars in the past 15 years and has lived in the same Madison, Wisconsin, suburb for nearly three decades.

Mark Zuckerberg – the sixth-richest person, with a net worth of US$63.6 billion – also lives a relatively low-key lifestyle.

His daily uniform consists of a simple T-shirt, a hoodie, and a pair of jeans.

And he and his wife, Priscilla Chan, ate McDonald’s food soon after their backyard wedding in 2012.

He has also been spotted driving relatively inexpensive cars, including an Acura TSX, a Volkswagen hatchback and a Honda Fit, all of which are valued at or less than US$30,000.

Jeff Bezos is also known to live modestly.

With a net worth of US$136 billion, Bezos is the richest person, but he used to drive a 1987 Chevy Blazer. In 2013, he was driving a Honda Accord.

Billionaires, CEOs, investors and businesspeople aren’t the only ones who live frugally. Some celebrities do not act like they are worth millions of dollars.

Consider Tyra Banks, who has always been more of a saver than a spender. One estimate puts the businesswoman, model, and producer’s net worth at US$90 million.

“While a lot of models were partying it up and going shopping and buying a wardrobe of designer clothes or staying at the top hotels during fashion week, I was at the DoubleTree or Embassy Suites, saving my money, and bought a house at 20 years old,” she once said.

“I was always more interested in experiences over things,” she told Money magazine. “Things didn't make me happy. I saved, saved, saved. But I saved to a fault.”

Her accountants told her she needed to spend money and had her set up a frivolous account, in which she had to budget to spend money on “stupid stuff”.

With the exception of his car collection, Jay Leno – who has an estimated net worth of US$350 million – is also quite the saver.

He has always tried to hold two jobs, spending the money from one job while saving money from the other.

Early in his comedy career, Leno also worked at a car showroom. He saved his comedy money and spent his car-dealership money.

When he hosted the Tonight Show, he saved all of his Tonight Show money – reportedly as much as US$30 million per year, according to CNBC – and spent only the money he made from stand-up-comedy touring.

Likewise, Jennifer Lawrence, who was born to a middle-class family, has always been thrifty.

“I was raised to have value for money, to have respect for money, even though you have a lot of it,” she previously said.

Even after Lawrence’s rise to fame and hefty pay cheques – she received US$15 million for the film Red Sparrow in 2018 – she lived for several years in the same three-bedroom apartment she got when she moved to Los Angeles.

She has been spotted driving a Chevy Volt, which has a US$39,000 price tag.

Lawrence loves to clip coupons. “I still look for bargains when I go to the market,” she said.

The actress and singer Kristen Bell also loves coupons – she has previously said she exclusively shops with them.

She is a big fan of Bed Bath & Beyond’s 20 per cent off coupons. “I may or may not have stolen them out of my neighbours' postboxes sometimes,” she told Conan O'Brien.

And her wedding with Dax Shepard cost just US$142, including the petrol to get to the courthouse.

That is pretty frugal for someone who reportedly earns US$125,000 per episode of the TV show The Good Place – and that is not counting her undisclosed earnings from the movie Frozen, which grossed more than US$1.2 billion at the box office.

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