Spur-of-the-Moment Decisions Highlight a Billionaire’s Giving

At the behest of a friend, David M. Rubenstein, the billionaire financier, agreed to underwrite $70,000 in awards to honor seven of Washington’s finest teachers. He wound up giving another $100,000 at the November event after discovering that an additional 20 teachers would have received awards if the group, the D.C. Public Education Fund, had had more money. “Sometimes I like to do it on the spur of the moment,” he says of his philanthropy.

Mr. Rubenstein, a