We analyze the influence of differences in the institutional design of transition from primary to secondary school on educational behavior of German children. More precisely, differences between binding teacher recommendations and free parental choice are evaluated w.r.t. transition rates to the respective school tracks and repetition rate in the first grade after transition. We exploit a recent policy reform in the state of Baden-Wuerttemberg that led to the abolition of mandatory teacher recommendations using the neighboring state of Bavaria as the control group. Developing a dis-aggregated version of the Synthetic Control Method, we use the 44 and 96 districts in Baden-Wuerttemberg and Bavaria respectively to derive a distribution of treatment effects, which is then compared against an analogous placebo in-time distribution. The abolishment of mandatory teacher recommendations led to a substantial increase (decrease) in the transition rate to the highest (lowest) school track. For the overall repetition rate in grade five, we find a positive effect amounting to an increase of about 86%.