This document is part of a Bridgespan Group research project that focused on the question: "How could a philanthropist make the biggest improvement on social mobility with an investment of $1 billion?" In answering this question, the authors have sought to understand "what matters most" for improving social mobility outcomes. To do this, the authors have drawn from extensive research conducted by leading scholars in the field. They have also outlined a range of tools to assist philanthropists seeking systemic and field-level changes that go well beyond scaling direct service interventions. Using the research and identified tools, the authors have created an illustrative set of "bets" that provide concrete roadmaps for high-leverage investments of $1 billion with the potential for sustainable change at scale. From a list of 15 high-potential bets through which philanthropists could have a significant impact on increasing upward mobility, six bets were selected that are particularly timely, suited to the unique role of philanthropy, have the potential to create significantly outsized impact, and, as a package, could truly sum to $1 billion. This concept paper illustrates one of the six bets. The paper discusses potential solutions to place-based barriers--such as limited job opportunities, restricted access to good schools, and high rates of crime--focusing on investments that help break apart the structural forces of economic and racial segregation that have created communities of concentrated poverty and that help improve conditions in distressed neighborhoods. [For the main report, "'Billion Dollar Bets' to Create Economic Opportunity for Every American," see ED606509.]