"I don't think being able to allocate capital means you're good at anything else," he says. He offers a metaphor to illustrate how he thinks about financial investing versus philanthropic investing. When evaluating whether to buy a stock, he says, he'll wait months or even years until he feels comfortable "swinging at easy pitches." But in philanthropy, "you're really trying to swing at balls other people have been missing," he says. Plus, "the data's kind of fuzzy."
From this interview.