Billionaires might be lining up in the US to join the so-called Gates pledge initiative, but so far it has little support outside of America, writes Katie Barker.
Forty billionaires have signed up to the pledge, whereby they agree to give away at least half of their fortunes to philanthropy during their lifetime or shortly after their death. But not one of them is based outside of the US.
That may be for many reasons, but a few stand out. One that appears to be more universal among the wealthy in Europe and Asia centres on a personality trait - being reserved about money.
"Traditional reserve in the UK is a barrier to this kind of conspicuous giving," said Musa Okwonga of the Institute for Philanthropy. "They are not as comfortable talking about wealth or engaging in such public philanthropy."
So it would also appear to be the case among the wealthy in Asia. Li Ka-shing, one of Asia's wealthiest individuals, was made to look a bit uncomfortable when asked whether he would give his fortune away to the Gates pledge.
He said: "I'm still very healthy and I'm very satisfied with what I am doing." The 82-year-old pointed out his foundation had donated over $1.2 billion in the past 30 years.
"The giving pledge is conspicuous giving on a large scale by a big group, which we have not yet seen in the UK for example," said Okwonga.
Another big reason for the lack of enthusiasm towards the Gates pledge outside of the US is tax. George Bull, head of tax at Baker Tilly, said: "There is a feeling in the UK that if you give a million to charity both you and the charity will end up with a tax investigation, such is the climate of tax suspicion in the UK now.
"Everyone acknowledges that the UK government needs to protect its tax revenues, but this should be done in a way that encourages philanthropic giving not discourages it," he said.
Wealthy families have traditionally been at the forefront of philanthropic giving, but large-scale, conspicuous acts such as that advocated by Buffett and Gates may not prove instantly appealing to families with big business interests outside of the US.
"Multigenerational business-owning families tend to be less public about their philanthropy. It is used to pass on family values and bring generations together. In contrast, public shows of philanthropy are about inspiring others to do the same so in their very nature must attract attention," said Okwonga.
The way the wealth was acquired can also play a role in determining the type of philanthropy wealthy families and individuals engage in.
"People will give their money away the same way they made it," said Okwonga. "Take Bill Gates, his success is based on communication and great marketing, so he transfers these business skills to his philanthropic activities.
"Entrepreneurs tend to be more comfortable using the media to help them succeed in business, so they take the same approach with their philanthropy," said Okwonga.