Forecasting Enrollments During Court-Odered Desegregation

Distinctive issues arise when a demographer must forecast enrollments in a context of court-ordered desegregation. The key issue studied here is whether magnet schools strengthen a district's overall attractiveness to enrollees from outside, or whether they only siphon students away from other nonmagnet schools within the district, achieving no net effect districtwide. One can clarify this issue by examining patterns of change in grade progression rates as magnet schools are phased in. In this case study, the magnet schools had enhanced the district's overall retention at most grades but did not produce actual increases at most grades. As often as not, they had merely slowed the overall weakening of retention districtwide. These insights furnished an important "reality check" on the necessary judgment for crafting appropriate forecasting assumptions. The resulting forecast tracked subsequent enrollments reasonably well and avoided exaggerated optimism. The pattern of error three years into the forecast period offers insight into the strengths and weaknesses of the approach.