Research on student progression in higher education has traditionally focused on vertical outcomes such as persistence and dropout, often reducing complex academic histories to binary indicators. While the structural component of horizontal mobility (major switching, plan changes, re-entries) has recently been recognised as a core feature of contemporary university systems, the temporal cost and efficiency of these pathways remain largely unquantified. Using forty years of administrative records from a large faculty of engineering and exact sciences in Argentina (N = 24,016), this study applies a dual-outcome survival analysis framework to two key outcomes: definitive dropout and first major switch. We reconstruct academic trajectories as sequences of enrolment spells and typed transitions under the CAPIRE protocol, and then deploy non-parametric Kaplan-Meier estimators to model time-to-event under right-censoring. Results uncover a critical systemic inefficiency: a global median survival time of 4.33 years prior to definitive dropout, with a pronounced long tail of extended enrolment. This pattern reveals a phenomenon of stagnant persistence, where students remain formally enrolled for long periods without commensurate curricular progression. In contrast, major switching follows an early-event regime, with a median time of 1.0 year among switchers and most switches concentrated within the first academic year. We argue that academic failure in rigid engineering curricula is not a sudden outcome but a long-tail process that generates high opportunity costs, and that institutional indicators should shift from static retention metrics towards measures of curricular velocity based on time-to-event analysis.

翻译：高等教育中学生学业进展的研究历来侧重于纵向结果，如学业持续与辍学，常将复杂的学术历程简化为二元指标。尽管横向流动的结构性要素（专业转换、计划变更、重新入学）近年已被视为现代大学体系的核心特征，但这些路径的时间成本与效率仍基本未被量化。本研究利用阿根廷一所大型精密科学与工程学院四十年间的行政记录（N = 24,016），采用双结局生存分析框架，聚焦两个关键结局：最终辍学与首次专业转换。我们依据CAPIRE协议将学术轨迹重构为注册时段序列与类型化转移序列，进而运用非参数Kaplan-Meier估计器在右删失条件下建模事件发生时间。结果揭示了一个关键的系统性低效现象：最终辍学前的全局中位生存时间为4.33年，且存在显著的延长注册长尾分布。该模式显现出“停滞性持续”现象，即学生长期保持正式注册状态却未获得相应的课程进展。相比之下，专业转换遵循早期事件模式，转换者中位时间为1.0年，且多数转换集中于第一学年。我们认为，刚性工程课程体系中的学业失败并非突发结果，而是产生高机会成本的长尾过程；机构评估指标应从静态保留指标转向基于事件时间分析的课程进度速率度量。