We need to find the colleagues and the friends and the competitors and the antagonists who unlock our genius and add their own. “Americans who live in metropolitan areas with more than a million residents are, on average, more than 50 percent more productive than Americans who live in smaller metropolitan areas,” Glaeser writes. “These relationships are the same even when we take into account the education, experience, and industry of workers. They’re even the same if we take individual workers’ IQs into account.”
