Tommy Andersson

We study school switches in which students who have already been assigned seats request
reassignment. Unlike in regular school choice, stability need not be legally binding in such
programs, since students’ priority-based claims have already been satisfied upstream. Effi-
ciency then naturally becomes the primary design objective. To quantify the potential legal
efficiency gains, we compare Deferred Acceptance (DA) with Top Trading Cycles (TTC) and
an efficiency-adjusted DA (EADAM) using Swedish data. TTC and EADAM triple switch-
ing rates compared to DA. This difference is driven by the absence of slack in effective
capacity and shrinks rapidly when introducing additional seats.