One of the Giving Pledge philanthropists and co-founder of Microsoft, Paul Allen, recently died. But at his death he was worth more than he was when he signed the Giving Pledge, a pledge that 186 of the wealthiest philanthropists have made to give away half of their net worth before they die.
This inspired Alana Semuels, writing in the Atlantic, to ask whether the Giving Pledge is realistic. When Allen signed the Pledge in 2010 he was worth $13.5 billion, when he died he was worth $20 billion. So despite the fact that he made many large donations to nonprofits during that time, he dramatically failed to meet his pledge.