The relationship between leadership style and staff work engagement: An empirical analysis of the public sector in Vietnam

The study investigates how transformational (TRF), transactional (TRA), and laissez-faire (LAF) leadership styles relate to staff work engagement (WE) and leadership outcomes—innovative work behavior (IWB) and task performance (TP)—among department-level leaders in Vietnam’s public sector. Motivated by gaps in evidence at the department level in Vietnam, where public administration is undergoing reforms and professionalization, the research examines whether TRF and TRA positively, and LAF negatively, relate to WE, IWB, and TP, and whether WE mediates these relationships. Hypotheses: H1–H2 posit positive links between TRF and IWB/TP and WE; H3–H4 posit positive links between TRA and IWB/TP and WE; H5–H6 posit negative links between LAF and IWB/TP and WE; H7 posits WE positively relates to IWB and TP; H8 posits WE partially mediates the effects of leadership styles on IWB and TP. The study aims to inform leader development and selection in the Vietnamese public sector.

Prior research across cultures generally finds TRF and TRA positively associated with employee engagement and performance, and LAF negatively related. TRF emphasizes idealized influence, inspirational motivation, intellectual stimulation, and individualized consideration, fostering trust, innovation, and performance. TRA relies on contingent reward and management-by-exception mechanisms to align effort and outcomes, which can enhance engagement and performance when well implemented. LAF reflects leader absence and nonintervention, often undermining engagement and performance unless staff are highly skilled and autonomous in strong cultures. Work engagement—defined by vigor, dedication, and absorption—has been linked to creativity, innovation, and performance, and often mediates leadership effects on outcomes. Evidence gaps remain in public sector and department-level contexts in Vietnam, justifying the present empirical test of these relationships and mediation.

Design: Cross-sectional survey using validated instruments to measure leadership styles, work engagement, innovative work behavior, and task performance. Participants and sampling: Cluster sampling of 378 Vietnamese public officials (department directors, deputy directors, and officials in the promotion pipeline) attending seven training classes at the Ministry of Culture, Sports, and Tourism’s Cadres Training and Development School, December 2021–May 2022. Informed consent and confidentiality were assured. Measures: • Leadership styles (TRF, TRA, LAF): MLQ-5X short form (Avolio & Bass, 2004), 36 items across nine facets (TRF 20 items; TRA 12 items including contingent reward, active and passive management-by-exception; LAF 4 items). Likert 1–5 (not at all to frequently, if not always). Cronbach’s alpha ranges: TRF 0.86–0.91; TRA 0.85–0.89; LAF 0.83–0.88. • Work engagement (WE): UWES-9 (Schaufeli et al., 2006), 9 items, three dimensions (vigor, dedication, absorption), Likert 1–5 (never to always), alpha 0.85–0.92. • Innovative work behavior (IWB): Janssen (2010) 9-item scale (idea generation, championing, implementation), Likert 1–5, alpha 0.92. • Task performance (TP): Kim (2014) 3-item scale, Likert 1–5 (strongly disagree to strongly agree), alpha 0.77–0.87. Instrument development: Questionnaire comprised leadership style items, WE, IWB, TP, and demographics (gender, age, experience, education, position, field). Data analysis: Computed descriptive statistics, internal consistency (Cronbach’s alpha; reliability 0.82–0.92 overall), Pearson correlations, and linear multiple regression analyses to test direct effects and mediation via WE. Model fit: SRMR = 0.046 (<0.08). Reported R2 and adjusted R2 (AR2), and effect sizes referencing Cohen’s guidelines. Mediation assessed by including WE as mediator (change in explained variance and path coefficients).

• Correlations: TRF correlated strongly with TRA (r=0.79, p<0.01), WE (r=0.74, p<0.01), IWB (r=0.73, p<0.01), and TP (r=0.61, p<0.01). LAF correlated negatively with WE (r=-0.46, p<0.01) and IWB (r=-0.34, p<0.01). • Regression: Leadership styles jointly explained WE (AR2=0.41, F=12.35, p<0.01), IWB (AR2=0.27, F=9.18, p<0.01), and TP (AR2=0.26, F=11.39, p<0.01). – TRF predicted WE (β=0.51, p<0.01) and IWB (β=0.27, p<0.05); effect on TP was not significant when controlling for other styles. – TRA predicted TP (β=0.34, p<0.01); effects on WE and IWB were not significant when controlling for TRF and LAF. – LAF negatively predicted TP (β=-0.23, p<0.01); effects on WE and IWB were not significant in the multivariate model. • Work engagement effects: WE significantly predicted IWB (β=0.61, ΔR2=0.30, F=15.57, p<0.01) and TP (β=0.57, ΔR2=0.28, F=12.13, p<0.01). • Mediation: Controlling for WE, TRF remained a significant predictor of IWB (β=0.37, p<0.01), suggesting partial mediation. TRA significantly predicted TP (β=0.41, p<0.01) with WE in the model, indicating WE’s partial mediating role. Overall, WE partially mediated the relationships between leadership styles and outcomes (IWB, TP). • Descriptive engagement and style levels suggested high TRF and WE means (TRF M=4.15, WE M=4.17).

Findings support that transformational leadership enhances employees’ engagement and innovative behavior and is associated with better task performance, aligning with prior cross-cultural literature. Transactional leadership is positively related to task performance, consistent with contingent reward and management-by-exception mechanisms driving results. Laissez-faire leadership undermines outcomes, showing negative associations with engagement and innovative behavior and a negative predictive effect on task performance. Critically, work engagement functions as a key mechanism connecting leadership styles to IWB and TP, with substantial incremental variance explained by WE and evidence of partial mediation for TRF→IWB and TRA→TP. In the Vietnamese public sector context, cultivating TRF and TRA at the department level can strengthen engagement and thereby improve innovation and performance, while minimizing laissez-faire tendencies is advisable.

The study advances leadership research by demonstrating that, among department-level leaders in Vietnam’s public sector, transformational and transactional leadership styles are positively associated with employee engagement and leadership outcomes (innovative work behavior and task performance), whereas laissez-faire leadership relates negatively. Work engagement plays a central, partially mediating role linking leadership styles to outcomes. Practically, leader selection and development should prioritize transformational and transactional capabilities and discourage laissez-faire tendencies. Future research should broaden beyond department level and central agencies, incorporate additional leadership styles and alternative measurement tools, and employ longitudinal or multi-source designs to strengthen causal inference.

• Cross-sectional design limits causal inference over time. • Self-reported questionnaires may introduce common method bias and may not fully capture constructs. • Focus restricted to three leadership styles (transformational, transactional, laissez-faire). • Sample limited to department-level leaders in central public sector agencies; generalizability to local levels or other sectors may be limited. • Reliance on MLQ-5X and specified scales; future work should triangulate with other instruments and data sources.