School choice is an education reform premised on a simple proposition: give families more choices, and they will find schools that best fit their children's needs. In short, school choice aims to create a marketplace of schooling options. School choice programs will succeed or fail based on how well they are able to create this marketplace and how deftly they can overcome issues on both the supply (schools) and demand (parents) sides of the school choice equation. Over the past several years, American Enterprise Institute (AEI), has been working to come to a more sophisticated understanding of both the demand and supply sides of school choice marketplaces. This report is a summary of what AEI has learned and a road map for those hoping to improve the design and efficacy of school choice programs in America. Several lessons are offered for improving the demand side of the school improvement equation. Improving the supply side means creating the conditions that help new schools open, and three key forces that shape the supply-side response of schools to school choice programs are outlined.