Employee loyalty (EL) is crucial for organizational success. This study focuses on EL within the context of higher education institutions (HEIs) in Vietnam, a rapidly developing economy facing increased competition. Several factors influence EL, including internal communication (IC), employee engagement (EE), and job satisfaction (JS). Effective IC facilitates information exchange and motivation, impacting EE and subsequently JS and EL. The study aims to investigate the interplay of IC, job engagement (JE), organizational engagement (OE), and JS in influencing EL within Vietnamese HEIs. Binh Duong province was chosen for its rapid growth, manageable scope for research, and potential policy implications. The post-COVID-19 environment and intense competition among HEIs make employee retention a critical priority. This research is novel in its focus on Vietnamese HEIs post-COVID-19, its application of social exchange theory, and its simultaneous examination of JE and OE as mediators in the relationship between IC and EL.

Social exchange theory (SET) underpins the study, suggesting a reciprocal exchange between employees and organizations. Effective IC, as a resource provided by the organization, is expected to enhance EE, including both JE and OE. Higher EE, in turn, leads to increased JS and EL. The literature review extensively examines the definitions and dimensions of IC, JE, OE, JS, and EL, citing numerous studies that support the hypothesized relationships among these constructs across various sectors. However, research specifically examining these relationships within the Vietnamese HEI context remains limited, creating a significant gap this study seeks to address.

This quantitative study employed an online questionnaire-based survey design to collect data from 255 respondents from four selected universities in Binh Duong province, Vietnam. Convenience and snowball sampling techniques were used. The questionnaire comprised six sections: demographics, IC, OE, JE, JS, and EL. A five-point Likert scale measured these constructs using adapted items from existing scales. Data analysis was performed using partial least squares structural equation modeling (PLS-SEM) via SmartPLS 3.0. The sample included a relatively even gender distribution, with most respondents aged 30-39, holding master's degrees and employed in public universities. The methodology ensured a high response rate (96.2%) and met minimum sample size requirements for PLS-SEM analysis, adhering to established standards for reliability and validity assessment. PLS-SEM was applied to assess the measurement model, testing for convergent and discriminant validity through indicators such as outer loadings, composite reliability (CR), average variance extracted (AVE), and the Heterotrait-Monotrait (HTMT) ratio.

The measurement model exhibited excellent reliability and validity. PLS-SEM analysis revealed significant positive relationships between: (1) IC and JS; (2) IC and JE; (3) IC and OE; (4) OE and JS; (5) JE and EL; (6) OE and EL; and (7) JS and EL. Hypothesis 2a, stating a positive relationship between JE and JS, was not supported. The results showed that OE significantly mediates the relationship between IC and both JS and EL. JE also significantly mediated the relationship between IC and EL. The R-squared values indicate that the model explains a substantial portion of the variance in both JS (78.4%) and EL (83.1%). Effect size analyses confirm strong effects of IC and OE on JS, and of OE on EL. The f-square values indicate strong effects of IC and OE on JS and a moderate effect of JS on EL.

The findings support the hypothesized model based on SET, demonstrating the significant influence of IC on JS, JE, and OE, which in turn positively affect EL. The mediating role of OE in the IC-JS and IC-EL relationships is particularly noteworthy, highlighting the importance of organizational-level engagement in fostering both satisfaction and loyalty. The lack of a significant direct relationship between JE and JS warrants further investigation. This study is unique in its context and contributes to the understanding of EL in emerging economies and HEIs. The results underscore the importance of implementing effective IC strategies and promoting organizational engagement to enhance employee loyalty within HEIs.

This study contributes significantly to understanding the factors influencing employee loyalty in Vietnamese HEIs. The findings highlight the critical role of internal communication, organizational engagement, and job satisfaction in fostering loyalty. The mediating role of engagement is crucial for HR strategies. Future research should explore this model in different contexts and investigate the moderating effects of other variables. Further research using longitudinal studies and different sampling methods could strengthen the findings and address the limitations.

The study's limitations include its focus on HEIs in Binh Duong province, limiting generalizability to other sectors. The cross-sectional design limits causal inferences. The use of convenience and snowball sampling might introduce bias. Future studies could address these limitations by employing larger, more diverse samples, longitudinal designs, and alternative sampling techniques.