Buffett and Gates Giving Pledge - asking US billionaires to donate 1/2 of wealth to charity

The Giving Pledge has a simple website which lists a number of US billionaires who have made a public commitment to donate at least half of their money to charity. http://givingpledge.org/ The letters are interesting to read. Some have criticized this initiative - some of the billionaires made their money in unscrupulous ways, some have given little proportionately so far to charity, some will end up giving funds to either pet causes or their own foundations who may only slowly dole it out over decades or longer, we need higher taxes and more services rather than more charity etc. Despite the criticism I still think the initiative is a good one and many US billionaires have already signed on.  Hopefully some Canadian billionaires will be inspired by this example and will also give away a significant portion of their wealth to charities doing good work in Canada and abroad. If Canada’s richest turn out to not be too generous we may want to think of implementing a US style estate tax!  Nothing like the possibility of having to pay a 40% tax, over and above 35% income tax, to encourage philanthropy before meeting your maker.