There’s been a lot of talk lately about design’s central role in our business lives. There’s been nearly as much buzz about how design, or at least design thinking, can solve big social problems. Cynthia E. Smith certainly thinks so. She highlights examples of this in her exhibition “Design for the Other 90%: Cities.” Projects in which the world’s poor have been “rescued by design” range from the favelas of Sao Paulo to the Kiberia slums in Nairobi to the canals of Bangkok. But as Michael Kimmelman points out in his review of the exhibition, these projects succeeded because the designers consulted the people living in poverty for their help in solving the problem. Human-centered design, as many of us have known for years, is the real key to designing lasting solutions to problems that people really care about.