A Broken Pledge

The super-rich who pledged to give away most of their money to good causes are instead sitting on rising wealth fueled by the "warehousing" of cash in dedicated family foundations or funds, a new study from the Institute for Policy Studies has found.

More than three-quarters of a group of US billionaires who signed up to the Giving Pledge to donate most of their money saw a significant rise in wealth over the last decade.

"The Giving Pledgers set out in 2010 to give away half their wealth and instead their assets have doubled," said Chuck Collins, co-author of the Gilded Giving report.

 51 out of the 62 American billionaires reviewed in the research saw "significant increases" in their net worth. 

This is partly because many are making money so fast that it has "outstripped" their capacity to give it away, the IPS said.

But it also highlighted concerns that many are choosing to put their charitable funds into private foundations and donor-advised funds that often save on tax and may end up "warehousing" money instead of getting it to just causes.

"They should give it directly to working non-profit charities and not to their own perpetual family foundations or donor-advised funds," Collins said.

The top 1 percent may hold 24 percent of global wealth by 2050, according to a recent United Nations report, as global wealth inequality steadily grows.