  Most US school districts draw "attendance boundaries" to define catchment
areas that assign students to schools near their homes, often recapitulating
neighborhood demographic segregation in schools. Focusing on elementary
schools, we ask: how much might we reduce school segregation by redrawing
attendance boundaries? Combining parent preference data with methods from
combinatorial optimization, we simulate alternative boundaries for 98 US school
districts serving over 3 million elementary-aged students, minimizing
White/non-White segregation while mitigating changes to travel times and school
sizes. Across districts, we observe a median 14% relative decrease in
segregation, which we estimate would require approximately 20\% of students to
switch schools and, surprisingly, a slight reduction in travel times. We
release a public dashboard depicting these alternative boundaries
(https://www.schooldiversity.org/) and invite both school boards and their
constituents to evaluate their viability. Our results show the possibility of
greater integration without significant disruptions for families.
