World's richest man would take 220 years to spend his wealth

Since the financial crisis, the number of billionaires in the world has more than doubled, according to research by Oxfam which warns that economic inequality has “reached extreme levels”.

According to the charity, the number of billionaires (US$) worldwide totalled 1,645 people by March 2014 - up from 793 billionaires in March 2009.

Calculations by Oxfam, which were published earlier this year, found that the 85 richest individuals in the world owned the same amount of wealth as the poorest half of the global population.

This figure was based on the total wealth of the 85 billionaires at the time of the annual Forbes list in March 2013. According to Oxfam’s latest research, in the 12-month period since the last Forbes report, their wealth has increased by 14%, or $244bn - equating to a $668m-a-day increase.

The global report on inequality released by the charity on Wednesday, warns that the “billionaire boom is not just a rich country story”. India, which had two billionaires in the 1990s now has 65, while by March 2014 there were 16 billionaires in sub-Sharan Africa.

In this latest report, Oxfam have calculated the length of time it would take the world’s richest people to spend their wealth. For Carlos Slim, the world’s richest man, it would take 220 years for him to spend his $80bn fortune at a rate of $1m per day.

As Oxfam say in the report: “Once accumulated, the wealth of the world’s billionaires takes on a momentum of its own, growing much faster than the broader economy in many cases”.

The chart below shows how much the world’s richest would make on their wealth per day in a savings account (at an ordinary rate of 1.9% interest and at an average billionaire rate of 5.3%).

Oxfam’s report, endorsed by Andy Haldane, chief economist at the Bank of England also analyses a tax of 1.5% on all the world’s billionaires. It found that if all the billionaires in the world were to be taxed at 1.5% (on wealth over $1bn, as of 2014) it could raise $74bn, or as the charity put it, “enough money to fill the annual gaps in funding needed to get every child into school and to deliver health services in the world’s poorest countries”.

Guardian economics editor, Larry Elliot writes today:

The report found that inequality between countries had widened rapidly between 1980 and 2002, before narrowing slightly due to the rapid growth in China. But it said that inequality had risen within countries, so that seven out 10 people lived in nations where the gap between rich and poor was greater than it was 30 years ago.

The charity which is calling for a seven-point plan to tackle global inequality, applaud Bill Gates and Warren Buffet in its report for their decisions to give away their fortunes, calling them “an example to the rest of the world’s billionaires”.

The report concentrates primarily on economic inequality but Oxfam note that ‘inequality’ can have “many different dimensions”:

Including race, gender, geography and economy, which rarely work in isolation. This report is primarily concerned with the concentration of financial resources and wealth in the hands of the few, which can affect political, social and cultural processes to the detriment of the most vulnerable.

As such, in this report we use the term ‘inequality‘ to refer to extreme economic (wealth and income) inequality. When referring to the various dimensions of inequality we make these distinctions.

• This article was amended on 30 October 2014 to correct the colours used in the key for the ‘top ten richest people by earnings’ graphic.