A defining feature of the American Dream is upward income mobility — the ideal that children will achieve a higher standard of living than their parents. Economist Raj Chetty’s research shows that children’s prospects of reaching that benchmark have fallen from 90 percent to 50 percent over the past half century. Chetty will discuss how big data can help us understand what has led to the erosion of the American Dream — and how local policymakers and civic leaders can use it to revive the Dream for future generations.