Impact of International Academic Mobility on Students' Perceived Employability: Mechanisms, Heterogeneity, and Robustness Analysis

International academic mobility is widely promoted as a strategic tool to enhance graduate employability (European Commission, 2022). However, although mobility has been widely associated with positive outcomes, the specific mechanisms through which it shapes students’ perceived employability remain underexplored.This study develops and empirically tests an integrated framework combining human capital (capability development), signalling value, and social capital mechanisms. Using survey data from N = 528 final-year students and recent graduates across six European universities, the study estimates a structural equation model (SEM) and complements it with propensity score matching (PSM) to address self-selection bias. Results indicate that mobility participation is positively associated with perceived employability (β = 0.34, p < .001). The relationship is partially mediated by capability development (β = 0.41, p < .001), signalling value (β = 0.26, p < .01), and social capital (β = 0.18, p < .05). Internship-based mobility exhibits stronger effects than exchange-based mobility (Δβ = 0.17, p < .01). Institutional support strengthens the mobility–employability relationship (β_interaction = 0.13, p < .05). PSM results confirm the robustness of the findings (ATT = 0.29, p < .01). The study clarifies the mechanisms linking mobility to employability perceptions and provides actionable implications for higher education policy and programme design. Taken together, the findings indicate that mobility benefits extend beyond experiential exposure and operate through identifiable psychological and relational processes. Keywords: academic mobility; perceived employability; signalling theory; social capital; structural equation modelling; Erasmus+