Despite the ongoing debate about how much academic versus vocational upper-secondary education is favorable for a country and large differences across countries of those two types of education exist, the interplay of vocational and academic education on upper-secondary level and its consequences for the entire education system remain under-researched. Although difficult to analyze directly, we first construct a measure to capture companies' reactions to changes in academic education rates and second analyze whether academic education rates are associated with success rates in vocational education over time and with control variables. To measure companies' reactions, we use a cantonal average requirements profile consisting of the academic requirements profile of an occupation and the number of apprenticeships started in this occupation per year and canton. Although results of the first part of the analysis are ambiguous, combined with the second part, they suggest a non-reaction of companies (i.e., they keep offering the same occupations but have to fill their positions with lower-ability candidates). Results of the second part show that more opportunities for academic education appear to draw highly-able students away from vocational education, with negative consequences for the success rates in vocational education. Our findings have important implications for countries with vocational and academic tracks in their education systems, but also for those who plan to introduce or strengthen (dual) vocational education.