U.S. singer Eartha Kitt is seen at the end of the Poor People March, on June 19, 1968, in Washington, D.C. (Photo by ARNOLD SACHS/AFP via Getty Images)Just give people money. It's the simple, brute-force solution to so many problems. In low-income countries, charities are sometimes measured against whether their interventions are better than simply giving people cash. Even in high-income countries like the U.S., when disaster strikes, often the best thing you can do is get money into the hands o...