Giving to selected causes by hugely wealthy individuals has yet to be proved as an answer to the world's ills, a new book claims.
In The Power of Giving: Philanthropy Debated, Michael Edwards, director of the Ford Foundation, defends his concept of 'philanthrocapitalism' - directed large-scale charitable giving from people such as Microsoft founder Bill Gates and investor Warren Buffett.
"Philanthrocapitalism is in part a symptom of a profoundly unequal world," writes Edwards. "It hasn't yet demonstrated that it provides the cure."
Also writing in the book, published this month, Colin Greer, president of the US New World Foundation, says that grant-making foundations must seek to become organisations promoting social justice rather than just grant givers.
"We do not operate on the principle that our long-term survival is the most significant consideration in the use of our resources," he writes.
"We must aim to be the change we seek, and this is as important for the foundation as for its grantees."