The origins of Home Depot, a big American home-improvements store, are inauspicious. In 1978 two of its co-founders were fired from senior roles at Handy Dan’s, a similar chain in southern California, in a power struggle. They decided to start a rival firm. In an effort to lure in customers on opening day, the co-founders’ children stood outside the doors and handed out dollar bills. “By dinner time they still had plenty of cash,”…