The Gates data is inspirational. Glad you put that in perspective. However, we need to see more data on the impact of the Giving Pledge, and whether it has led

The Gates data is inspirational. Glad you put that in perspective. However, we need to see more data on the impact of the Giving Pledge, and whether it has led to more giving. In your chart, the assumption is that this money is more than would have been given without the Pledge. Also, the comparison to amount pledged (most of which will eventually make its way into foundations that will spread the money on their own time schedules) with the amount donated in 2014 is not a telling comparison. Consider, for example, my billionaire mother. Before she died, a couple of years ago, we discussed whether she should be joining The Giving Pledge. She decided she didn't want to be seen in the company of billionaires who had pledged to give away only 50% of their money. "Why would a billionaire want to keep half of their money, anyway? What could someone possibly do, personally, with half a billion dollars? I don't want to join a group like that!" To understand the impact of The Giving Pledge we'd need to know how much would have been given without the pledge? Does the Pledge provide peer pressure to give away more than they would have otherwise given? Or does this pledge lead to less giving, because it makes billionaires feel that it's morally OK to give away just 50%? Do you have the comparison data to answer these questions?