In a report it says outlines the "extreme, unsustainable and unjust" economic inequality in the world, Oxfam estimates the richest eight people on the planet have the same wealth as half the world's population.

Forbes' rankings of the world's richest people includes in its top eight Microsoft founder Bill Gates (net worth $75 billion), investing guru Warren Buffett, Amazon owner Jeff Bezos and Facebook CEO Mark Zuckerberg.

Between them, Oxfam says they have as much wealth as the poorest half of the world – 3.6 billion people – and it says this growing inequality "threatens to pull our societies apart."

Last year, Oxfam's report said that 62 people had the same wealth as the bottom half of the global population, but this has been revised down following new information gathered by Credit Suisse.

Singling out just a handful of predominantly self-made billionaires may be unfair to make a point about inequality (Bill Gates, for example, has a charity foundation that actually works to reduce inequality, and he and Warren Buffet are in favor of higher taxes on the rich), but it is the corporate world they represent that is the main focus for the global poverty charity's ire.

Corporations blamed for inequality

While there are several causes for financial inequality, with this report by the International Monetary Fund highlighting several – with education levels, trade, union membership and access to technology among them – the Oxfam report focuses mainly on the role of globalization and corporations.

Corporations who "increasingly work for the rich," it says, are denying economic benefits to those "who need them most" as the highest returns are enjoyed by those at the top, while lower-rung workers are "squeezed ... ever harder."

The same is said for those companies that take advantage of every loophole and back door possible to limit their tax payments, which in turn could be used to provide help for the poorer people in society, and using their financial clout to buy influence at the political level.

Its findings are in spite of the fact that fewer people around the world are in extreme poverty than ever before in history, but the charity says that if the economic growth seen over the past 25 years had been weighted towards the poor instead of the rich (see the table below), an extra 700 million people would not be in poverty today.

Oxfam suggests that to battle inequality, governments should take efforts to stop offshore tax dodging, raise the minimum wage, fight discrimination and ensure equal pay for equal work, improve access to affordable healthcare and education, and invest in a "social safety net for everyone."

A note on the calculations

Oxfam has attracted a bit of criticism in some quarters for the way it compiles these figures – not least as described in these pieces by Fusionand Heat Street.

The reason is that the figures are based on everyone's "net worth" – their assets minus their liabilities. As such, someone who has just taken out a mortgage or who has large student loans could be included in the bottom 50 percent even though they are earning a decent amount of money.

Fusion points out that debt isn't always a bad thing– for example there are positive outcomes to those borrowing money to start a business or to get a college degree – and it doesn't necessarily mean people are being left destitute.

Oxfam does address this complaint in its report, and says that while factoring the "net debt" of people would change the calculation, the number of people who have that combination of medium/high debt and medium/high incomes is not that significant.

With liabilities taken out of the equation, it would still mean the richest 56 people in the world have the same wealth as half the world's population.