Jeff Bezos's ex-wife MacKenzie Scott gives away $5.9bn in four months

In a round of donations early this year, Ms Scott gave nearly US$1.7bn to groups devoted to race, gender and economic equality, as well as other social causes.

Her wealth grew by US$23.6bn this year to over US$60bn, making her the world's 18th richest person.

The latest round of donations means she has given away around US$5.9bn this year, just under one tenth of her total wealth, or 16.6pc of her original divorce settlement.

The Charities Aid Foundation's Mark Greer said: "I can't think of anyone who has given away so much so quickly. It is especially gratifying to see that the money can be used by charities to pay for everyday costs."

Ms Scott said: "This pandemic has been a wrecking ball in the lives of Americans already struggling. Economic losses and health outcomes alike have been worse for women, for people of colour, and for people living in poverty."

Meanwhile, she noted, the wealth of billionaires has substantially increased.

The donations have placed her among a cohort of philanthropic billionaires who have given away vast sums in recent years. According to Forbes, last year Indian business tycoon Azim Premji gave away a US$7.6bn stake in IT firm Wipro Limited to his own charity The Azim Premji Foundation.

Warren Buffett also gave away some US$3.6bn in Berkshire Hathaway stock last year to the Bill and Melinda Gates Foundation among others, bringing his total donations to US$38bn.

Ms Scott's ex-husband Mr Bezos also announced an initial 16 recipients for his US$10bn Earth fund, with grants to the World Wildlife Fund and others totalling US$791m.

In Britain, former Sainsbury's chairman Lord Sainsbury, Wolfson Foundation chairman Dame Janet de Botton and hedge fund manager Sir Chris Hohn are among the country's most generous philanthropists according to the Sunday Times Giving List 2020.

Charities face shortfall despite rise in will giving

British charities are facing a £10bn funding shortfall this year as a result of the Covid pandemic, despite the number of wills containing charitable donations of more than £1m rising.

This is likely down to millionaires looking to take advantage of generous inheritance tax breaks by gifting significant chunks of their restates to good causes, experts said.

Big donations benefit from a large death tax discount, which sees the rate drops from the typical 40pc to 36pc if at least a tenth of an estate is left to charity.

According to the National Philanthropic Trust, around two thirds of Britons donate to charity, giving an average monthly donation in 2018 of £45.

Medical research, animal welfare, hospitals and hospices, and children or young people were the most popular causes to donate money to.

According to the NPT, young people are more likely to give to physical and mental health care charities, refugees and shelters for the homeless, as well as to educational institutions. Older people are more likely to donate to hospitals, disaster relief, and religious charities.

Ms Scott was left a multi-billionaire after her divorce last year from Mr Bezos. She ranked 20th on a Forbes real-time list of the world's richest people index on Tuesday, with a net worth of US$56bn – after taking her latest donations into account.

Mr Bezos was at the top of that list with a net worth of US$185bn.