What would it take?

That was the question that Geoffrey Canada found himself asking. What would it take to change the lives of poor children , not one by one, through heroic interventions and occasional miracles, but in big numbers, and in a way that could be replicated nationwide? The question led him to create the Harlem Childrens Zone, a ninety-seven-block laboratory in central Harlem where he is testing new and sometimes controversial ideas about poverty in America. His conclusion: if you want poor kids to be able to compete with their middle-class peers, you need to change everything in their lives, their schools, their neighborhoods, even the child-rearing practices of their parents. Whatever It Takes is a tour de force of reporting, an inspired portrait not only of Geoffrey Canada but also of the parents and children in Harlem who are struggling to better their lives, often against great odds. Carefully researched and deeply affecting, this is a dispatch from inside the most daring and potentially transformative social experiment of our time.

Paul Tough is the author, most recently, of "Helping Children Succeed: What Works and Why." His previous book, "How Children Succeed: Grit, Curiosity, and the Hidden Power of Character," was translated into 27 languages and spent more than a year on the New York Times hardcover and paperback best-seller lists. His first book, "Whatever It Takes: Geoffrey Canada's Quest to Change Harlem and America," was published in 2008. He is a contributing writer to the New York Times Magazine, where he has written extensively about education, parenting, poverty, and politics. His writing has also appeared in the New Yorker, the Atlantic, and GQ and on the op-ed page of the New York Times. He has worked as an editor at the New York Times Magazine and Harper's Magazine and as a reporter and producer for the public-radio program "This American Life." He was the founding editor of Open Letters, an online magazine. He lives with his wife and two sons in Montauk, New York.