Yes, if I may, part of the issue with corporations giving, especially publicly listed corporations, is a fundamental philosophical discussion about how appropriate it is for corporations to be giving away revenue that would otherwise go to the shareholders. It might be that no matter what tax incentives you put in place, you're not going to be able to overcome that philosophical discussion as to what right they have to distribute money, when in fact it could go to the shareholders and back to the charity.
On February 9th, 2012. See this statement in context.