For decades, millions of American children have been assigned to a public school. Those who live in neighborhood A, for example, must go to school A. The reasons for this were, initially, easy to understand – transportation ease and neighborhood cohesion were thought to be part of the equation. But policies of racial discrimination were also at play. As states seek to innovate and improve public schools, open enrollment for all children must be at the top of the list of policy reforms. And transparency regarding a state’s open enrollment policies should be paramount.