Diversity management and organizational citizenship behavior in Thai public utilities: examining the dual mediating effects of organizational justice and organizational trust

Purpose This study aims to examine how diversity management influences organizational citizenship behavior (OCB) and it explains this relationship through the mediating roles of organizational justice and organizational trust in a public-sector context. Design/methodology/approach Using survey data collected from 407 employees of a state-owned public utilities organization in Thailand, the study tests a parallel mediation model using covariance-based structural equation modeling (SEM). Findings The study's findings contribute valuable insights into how organizational contexts shape the effectiveness of diversity-related human resource (HR) practices, leading to enhancements of employees' extra-role behavior. The results reveal that employees' perceptions of diversity management are positively associated with OCB at the total-effect level. However, this relationship becomes nonsignificant when organizational justice and organizational trust are included, indicating full mediation. Both organizational justice and trust serve as key psychological mechanisms through which diversity-related HR practices translate into employees' discretionary, extra-role behaviors. Practical implications The findings suggest that public-sector organizations should embed diversity management into core HR practices and simultaneously strengthen fairness and trust perceptions to effectively promote OCB and long-term organizational effectiveness. Originality/value Drawing on social identity theory, this study advances diversity management research by unpacking the psychological “black box” that links diversity-related HR practices to OCB through a dual-mediation framework. By integrating organizational justice and organizational trust within a single model and examining these relationships in a Thai public-sector setting, this study extends existing theory beyond predominantly Western and private-sector contexts.