Abstract
This study targets post‑1995 highly‑educated secondary‑school teachers in China. Despite accumulating evidence on perceived overqualification (POQ), few longitudinal studies have unpacked its temporally ordered predictive effects on teacher work engagement within educational contexts. Drawing on Relative Deprivation Theory and Self‑Determination Theory, this study adopts an 18‑month three‑wave time‑lagged longitudinal design and constructs a moderated‑mediation model where harmonious work passion (HWP) serves as the mediator and humble leadership (HL) acts as the boundary condition. Based on valid three‑wave data from 498 teachers, hierarchical regression, 5000‑time bootstrap tests and supplementary sequential path analysis are conducted to test the hypothesized temporal predictive associations. Statistical results indicate that POQ exerts significant negative predictive effects on both HWP and work engagement, HWP fully mediates the POQ‑work engagement linkage, and humble leadership buffers the detrimental POQ‑HWP association; when teachers perceive high‑level humble leadership, POQ’s negative influence on intrinsic work passion is weakened, which further attenuates POQ’s indirect adverse effect transmitted via HWP, and time‑lagged results support unidirectional lagged predictive paths that T1 POQ predicts T2 HWP and T2 HWP predicts T3 work engagement. Theoretically, this research establishes an integrated dual‑theoretical framework, validates HWP’s exclusive full‑mediating role among teacher samples, and introduces humble leadership as a novel contextual moderator for education. Practically, school administrators can implement job enrichment, build multi‑layered career pathways and foster humble leadership among supervisors to mitigate qualification‑mismatch‑triggered losses and sustain stable teacher work engagement. This study extends the boundary conditions of POQ research and provides operable strategies for K12 institutions to retain high‑credential young educators.