Emerging industries in China, particularly biopharmaceutical companies, are crucial for social development but face high turnover rates among technical personnel. This necessitates effective leadership that prioritizes employee well-being and engagement. Ethical leadership (EL), which integrates moral values into organizational practices, is seen as essential for improving organizational performance and reducing turnover. Previous research has highlighted the positive impact of EL on employee outcomes like work engagement and motivation. However, fewer studies have explored the relationship between EL and spontaneous organizational citizenship behavior (OCB), particularly differentiating between internal and external job satisfaction (IJS). This study aims to address this gap by examining the mediating role of IJS in the relationship between EL and OCB, and the moderating role of leader empathy (LE). The research focuses on R&D personnel in China's emerging industries because their innovation is critical to these sectors' sustainable development and they are particularly susceptible to high turnover.

The study draws upon self-determination theory (SDT) and emotional contagion theory (ECT) to frame its hypotheses. SDT emphasizes the importance of meeting employees’ intrinsic needs to foster motivation and positive behaviors. ECT suggests that leaders’ emotions can influence their followers’ emotions and behaviors. Existing research establishes a positive relationship between EL and job satisfaction, and between job satisfaction and positive work outcomes like OCB. However, studies often treat job satisfaction holistically, neglecting the distinction between IJS and external job satisfaction. This study argues that IJS, focusing on meeting employees' psychological needs, plays a key role in mediating the effect of EL on OCB. Furthermore, leader empathy (LE), characterized by understanding and supporting subordinates, is hypothesized to moderate the relationship between IJS and OCB, potentially amplifying or attenuating the positive effect of IJS on OCB.

A purposive sampling method, followed by snowball sampling, was used to recruit 248 R&D personnel from biopharmaceutical, new energy vehicle, and high-end equipment manufacturing companies in China. Data were collected in two stages using online questionnaires, with the first stage focusing on biographical information, EL, and IJS, and the second stage on LE and OCB. Seven-point Likert scales were used to measure the constructs: EL (adapted from Steinmann et al., 2016), IJS (adapted from Furnham et al., 2021), LE (adapted from Mahsud et al., 2010), and OCB (adapted from Lee and Allen, 2002). Partial least squares structural equation modeling (PLS-SEM) was employed to test the hypotheses, with Hayes' PROCESS macro used for moderation analysis. Common method bias (CMB) was assessed using Harman's single-factor test and the ULMC approach, revealing no significant CMB. The reliability and validity of the measurement model were also assessed and confirmed.

The results confirm several key relationships: First, ethical leadership (EL) is positively and significantly associated with internal job satisfaction (IJS) (β = 0.818, t = 23.98, p < 0.01). Second, IJS is positively and significantly associated with organizational citizenship behavior (OCB) (β = 0.320, t = 3.226, p < 0.01). Third, IJS fully mediates the relationship between EL and OCB (β = 0.431, SE = 0.192, CI excluding 0). Fourth, leader empathy (LE) negatively moderates the relationship between IJS and OCB (β = -0.128, t = -2.503, p < 0.05). This means that higher levels of LE attenuate the positive impact of IJS on OCB. The R-squared values for IJS and OCB were 0.668 and 0.818 respectively, indicating a good model fit. The model also showed strong convergent and discriminant validity. The structural model exhibited excellent fitness characteristics with R² values exceeding 0.5 and positive Q² values for both IJS and OCB. The SRMR value was below the threshold of 0.08, further supporting the model fit.

The findings support the study’s hypotheses and provide valuable insights into the relationships between ethical leadership, internal job satisfaction, leader empathy, and organizational citizenship behavior among R&D personnel in emerging industries. The mediating role of IJS highlights the importance of meeting employees' intrinsic psychological needs to foster pro-organizational behaviors. The negative moderating role of LE suggests that while empathy is valuable, it does not necessarily translate directly into increased OCB in this specific context. This contrasts with some previous findings emphasizing the positive effects of LE. It is argued that in the specific context of R&D personnel in high-pressure, rapidly changing industries, a focus on fairness and justice, rather than purely emotional support, is more effective in motivating positive work behaviors. The use of SDT and ECT provides a robust theoretical framework for understanding the complex interplay of these factors.

This study contributes to the leadership literature by clarifying the mediating role of IJS and the negative moderating role of LE in the relationship between EL and OCB, particularly within the context of China's emerging industries. It underscores the importance of ethical leadership practices focused on fairness and justice, alongside fulfilling employees' intrinsic psychological needs, to promote OCB. Future research could explore other contextual factors, including cultural differences, which might influence these relationships, as well as examine the generalizability of these findings beyond the specific industries studied.

The study is limited by its focus on R&D personnel in specific emerging industries in China, which may limit the generalizability of the findings. Future research should expand the sample to include a broader range of industries and geographic locations. The reliance on self-reported data also necessitates caution in interpreting the results. Further research could explore other moderating variables that might influence the relationship between IJS and OCB.