In recent years several municipalities in Sweden have merged their public secondary schools. This has been considered a type of initiative that intends to reduce youth segregation and discrepancies in school quality. This thesis examines in what ways the merging of all public secondary schools in a municipality affects the students’ academic performance and their choice to enroll in the publicschool sector. To do so I use municipality-level aggregate data from the Swedish National Agency for Education on 9th grade students’ academic outcomes and the share of 7th graders enrolled in the public schools. I employ a difference-in-difference approach to estimate the reduced form effect of the school mergers. The control group used in the baseline estimation includes all municipalities that had a constant number of public secondary schools during the time period of my study. I move on to use propensity score matching in order to create a more comparable control group. I then estimate a difference-in-difference regression with match-fixed effects. The results show that the mergers have a negative effect on the municipality-level average GPA. In addition, the municipalities where the mergers have been implemented experience a reduction in the share of students that pass all 9th grade subjects as well as an increase in the share of students who do not have sufficient grades to continue to upper secondary school. The school mergers caused the share of 7th graders enrolled in the publicschool sector to decrease by approximately 10 percentage points. These results indicate that the public secondary school merger is not a panacea for improving student outcomes.