Gary Philbin, CEO of Dollar Tree, said his company’s namesake chain and Family Dollar benefited from stimulus checks sent to Americans. Mr. Philbin said the checks were like tax refunds “on steroids” for the customers who shop in his company’s stores. “It’s gone a long way to help our customer have money in their pockets during this critical time,” he said. “The further we get away from that, it will be interesting to see how customers respond,” he added.