In the aftermath of a Supreme Court decision this year invalidating race-based school assignment systems, Cambridge’s “controlled-choice” policy, which strives to balance the schools by socio-economic characteristics, has been cited as a national model for school desegregation.

Under the controlled-choice plan, parents write down their top choices among the district’s 12 primary schools. Rather than assign students to schools by neighborhood, the district balances parent preferences with socioeconomic characteristics to determine which school each child will attend.

Currently, the school system is approximately 55 percent “paid lunch,” while 45 percent of students qualify for the federal free and reduced lunch program—often used as a proxy for low-income students. Under the controlled-choice system, there is a 10 percent “band,” meaning every school must be between 65 percent and 45 percent paid lunch.

But this year, Cambridge saw an influx of more middle class students at the kindergarten level—approximately two thirds of the first group to sign up for kindergarten were “paid lunch.” Some have questioned whether the formulas used by the district should be adjusted in order to allow more flexibility, which would allow more parents to receive one of their top choices.

The School Committee considered two temporary solutions: raise the paid lunch target to 66 percent—which would allow the schools to be between 56 percent and 76 percent paid lunch—or keep the 55 percent target and increase the “band” to 15 percent, which would mean the schools could be up to 70 percent paid lunch.

Ultimately, the committee, chose to increase the band, fearing that the schools would become imbalanced if it chose the first solution and changed the target.

If the influx of more affluent students continues, the School Committee has made clear that it will have to find a more permanent fix to the controlled-choice program, either through changing the target and changing the band, or using some measure other than free-and-reduced lunch.

This year, Superintendent of Schools Thomas D. Fowler-Finn and School Committee member Nancy K. Walser supported changing the target, while the others, led by Joseph G. Grassi and Patricia M. Nolan ’80, decided instead to increase the band—a solution that was deemed less threatening to the goal of maintaining desegregated schools.

While no candidates have run on a platform of repealing or significantly weakening the controlled-choice plan, it’s an open question what changes will be made to it in the future.