According to Virtanen and Tammeaid (2020), servant leadership is more “de-leadership” than traditional leadership styles. ²³ Greenleaf described it as a “conscious lifestyle”, which begins with self-awareness of serving desire, ⁶ laying the groundwork for later research. ¹ Spears defined servant leadership as “listening, empathy, healing, awareness, persuasion, conceptualisation, vision, management, commitment to people’s development, and community building”, which has been disputed subsequently. ²⁴

Some focus on optimisation, such as van Dierendonck and colleagues (2011), ²⁵ who compiled six aspects of servant leadership: empowerment, management, authenticity, humility, interpersonal acceptance, and guidance, ¹⁴ which is more concise than Spears’. ²⁶ Others focused on comparisons. Eva et al. more accurately defined servant leadership as three aspects: motivation (“other-oriented leadership approach”), model (“one-on-one interaction between leaders and followers”), and mentality (“overall concern for the well-being of others”), after comparing servant leadership and transformational leadership, authentic leadership, and moral leadership. Although different definitions have been created, the construct of servant leadership has yet to be proven, raising doubts about the validity of corresponding empirical study findings. ^{17, 27}

Leadership is frequently emphasised as a key aspect in the change process of public organisations, just as it is in private organisations. ^{28, 29} Unlike the private sector, public organisations are typically distinguished by bureaucratic structures and formal regulations, ³⁰ putting leaders to the test. ³¹

Servant leadership originated in the 1970s. During this period, the shaping of leadership roles gradually shifted from job roles focusing on organisational performance to service roles focusing on organisational behaviour to achieve reciprocity between leaders and followers. Regarding adaptability, servant leadership is considered a natural model for public organisations. ³² In recent years, leadership research has shifted its focus from the personal attributes of leadership style to the relational attributes of leadership style. ²⁶ Under the constraints of job attributes and job functions, leaders of public organisations have more opportunities to demonstrate service intentions than leaders of private organisations. ²⁶

Servant leadership originated in the 1970s. To promote reciprocity between leaders and followers, leadership roles were gradually modified from work roles focusing on organisational performance to service roles focusing on organisational behaviour. In terms of adaptability, servant leadership is regarded as a natural paradigm for public sectors. ³² Recently, leadership research has switched attention from leading qualities to relational attributions. ²⁶ Leaders of public organisations have more opportunities to exhibit service intents than leaders of private organisations, subject to obligatory limits. ³³ Therefore, shaping the leadership “servant” position is more reasonable in the public sector. ^{20, 34– 38}

Public sectors need an ethical leadership style. Servant leadership has emerged as an ethical leadership style over the last two decades. ³⁹ Unlike transformative leadership of the same emergence, servant leadership focuses on constructing learning organisations. More and more scholars have demonstrated the impact of servant leadership on the ethical atmosphere ²⁰ and suggest that it can guide organisational ethical norms to provide services more effectively. ⁴⁰

PRISMA facilitates critical appraisal by other researchers and practitioners by providing clear and comprehensive reporting, which enables others to replicate the review process, thus contributing to the body of evidence and knowledge in the field. ^{41– 43} PRISMA is widely recognized and accepted by top academic journals, making it a preferred choice for researchers aiming to publish their systematic reviews and meta-analyses. ^{44– 48}

By adhering to PRISMA guidelines, researchers can ensure that their reviews are conducted with a high level of methodological rigor. ^{43, 49} This helps in minimizing biases, enhancing the validity of the findings, and providing a clear, structured approach to reviewing the literature. ⁵⁰ Therefore, to ensure a reproducible, rigorous, and transparent procedure, this review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. ⁴⁹

There is no protocol exists for this systematic review, a thorough literature search was done across six academic electronic databases (Taylor & Francis, Sage, Scopus, Springer Link, Web of Science, and Wiley) to find published research on servant leadership in the public sector. The selection of these six databases ensures a comprehensive, multidisciplinary, and high-quality literature search.

Specifically, Taylor & Francis is a leading publisher of scholarly journals across disciplines. ⁵¹ Sage is known for its strong portfolio in social sciences. ⁵² Scopus is one of the largest abstract and citation databases of peer-reviewed literature, ensuring an inclusive search. ⁵³ SpringerLink offers access to a vast collection of academic research. ⁵⁴ Web of Science includes citation indexing and analysis, invaluable for understanding the research landscape. ⁵⁵ Wiley offers a diverse collection accessing to high-quality research that are pertinent to the search topic. ⁵⁶ Therefore, each database offers unique strengths in terms of coverage, relevance, and access to influential research, making them collectively suitable for an in-depth review of servant leadership in the public sector.

Keywords were combined with AND/OR Boolean phrases to search the literature. To ensure that the literature in the various contexts of the public sector was covered as comprehensively as possible, full-text articles containing the words “servant leadership” AND (“public agency” OR “public sector” OR “public administration” OR “public department” OR “government” OR “public service” OR “public centre”) were searched (Details are shown in Table 1).

The following criteria were required for research to be included in this review: First, as with prior reviews, ^{25, 57, 58} this review exclusively considers research written in English. Second, it omitted works published before 2019, as they were almost completely covered in earlier reviews. ^{22, 59– 61} Third, book chapters, book reviews, reviews, lectures, brief communications, conference papers, encyclopedias, editorials in non-academic journals, and other non-research article genres were removed to ensure the review’s quality. Finally, the articles were restricted to research contexts in the public sector (Details are shown in Table 2).

All content searches were done on the articles created during the search process to ensure that no records were overlooked. The complete texts of the research related to the titles and abstracts were then collected to identify the final publications relevant to the current study’s predefined research questions. ⁶²

The publications were sorted based on their title, year of publication, research environment (country), research design (conceptual, empirical), sample size, type, and results. The article parameters were summarised in Excel to systematically synthesise research on public sectors servant leadership. ⁴⁹ To prepare data for synthesis, we first dealt with missing summary statistics by contacting the corresponding authors for missing values. Where data could not be retrieved, the studies were excluded from the analysis. Krippendorff claims that content analysis has the advantage of “providing replicable and valid inferences from text (or other meaningful content) to the context in which it is used”. ⁶³ The present research analyses the content of writings on servant leadership in the public sector literature. ⁶⁴

First, an inductive approach was used to construct first-order codes describing servant-leadership traits (e.g., “emotional healing”). ⁶⁵ The appropriate first-order codes were then grouped into themes (N = 32) that more broadly characterized servant-leadership behaviours (e.g., “being attuned to other people’s feelings and activities”). Finally, these themes (second-order codes) were grouped into seven categories: “Other Oriented”, “Community Vision”, “Relationship Moderator”, “Trust with Empowerment”, “Professional Convincible”, “Moral Model”, and “Self-regulated”. Next, this study extracted research variables (antecedents, mechanisms, outcomes, and moderators), servant leadership measures, and underpinning theories from a subsample of quantitative articles (N = 45) and mapped a nomological network of servant leadership research in the public sector. ²²

The certainty of the body of evidence for each outcome was assessed using the GRADE approach. The risk of bias in the 51 studies included was assessed using validated tools appropriate for the study types. Randomised controlled trials were evaluated using the Cochrane Risk of Bias Tool, while non-randomised studies were assessed with the ROBINS-I tool. Two independent reviewers analysed each study across critical domains: selection, performance, detection, attrition, and reporting biases. Discrepancies between reviewers were resolved through discussion, and a third reviewer was consulted when necessary to achieve consensus. Automation tools, Rayyan, were utilised for the initial screening of abstracts and titles to identify relevant studies and exclude irrelevant or duplicate records, ensuring a streamlined process. The risk-of-bias examination was conducted manually to guarantee thorough assessment and precision. This rigorous method guaranteed the dependability of the incorporated studies and their results.

The research that was eventually screened out included one conceptual paper, ⁶⁶ five qualitative investigations, and forty-five quantitative studies. No studies with mixed methods designs were screened. ⁶⁷ Quantitative research reviewed (N = 45) analyzed data at several levels of quantification, validating the sample’s diversity. Flotman and Grobler (2020) investigated a scale. ⁶⁸ Five studies collected data from both employees and supervisors, ^{69– 73} examining dyadic relationships using structural equation modelling techniques. ^{74, 75}

Five trials used numerous time points. ⁷⁶ Regarding the sampling topics, two research remained fixed at separate survey dates, studying employee ideas. ^{77, 78} The following three research varied in time, but they mostly double-sampled employees and leaders to prevent common technique bias. ^{69, 70, 73} Most research controlled for one month, ^{69, 70, 78} while two studies used half a month ⁷³ and a year. ⁷⁷ Most studies limit the sampling frequency to three times or less. Most research designs employ two-time sampling, ^{69, 70, 73} while the remaining two use three-time sample. ^{77, 78}

The sample size for survey-based quantitative studies varied from 123 to 9,547 people (mean = 737, median = 347). Table 3 displays the geographical distribution and study design of the empirical studies examined. Empirical research on servant leadership in the public sector demonstrates a continental spreading trend toward poorer countries. According to Table 3, most articles came from Asia (N=31), followed by Africa (N=7), Europe (N=5), and North America (N=2). In terms of country distribution, it was conducted in 19 countries, with Pakistan (20.0%), China (15.6%), South Korea (8.9%), and Vietnam (8.9%) receiving the most. Compared to research characteristics before 2019, ²² the research background of servant leadership in the last six years has been increasingly oriented toward developing countries. This shift reflects the promotion of servant leadership methods in developing nations, as well as the application of servant leadership to resource management practices. ⁶⁴

The data collection strategy for empirical research on servant leadership in the public sector is cross-sectional. Table 3 shows that 88.9 percent of the 45 empirical research used cross-sectional data collecting. Asia has 27 articles, Africa has 7, Europe has four, and North America has two. On the contrary, the current study does not use the Time-Lagged data-gathering approach, and future research should focus more on this method. Table 3 shows that only five studies used the Time-Lagged data-gathering strategy. Four of them are in Asia, while one is in Europe. Overall, research on the Time-Lagged data collection approach is limited (Details are shown in Table 3).

Three interviews and two case studies are among the five studies on qualitative servant leadership in the public sector. The two case studies are a longitudinal case study and a qualitative case-based comparative analysis. ²⁶ In comparison to the quantity of quantitative studies conducted over the last six years, qualitative research on servant leadership in the public sector is limited.

The five qualitative studies discuss the characteristics of servant leadership in public relations, ⁶⁵ the possible conditions for servant leadership, ⁶⁶ the practical benefits of servant leadership, ⁶⁷ the potential impact on the internalization process of servant leadership, ²⁶ and the changes that may be brought about by the application of servant leadership. ⁶⁸ The research viewpoints are rather diverse and have research potential.

The sample sizes used in these qualitative investigations range from 3 to 159. Three interview studies decided to sample leadership, ^{65– 67} whereas two case studies chose to sample ordinary personnel of two public businesses and three public utility departments. Furthermore, all four qualitative investigations addressed the same country setting. The only case-based comparison study examined local government agencies in two nations and one city. ⁶⁸ The only published conceptual study on servant leadership looked at the conditions and role of servant leadership in public education, highlighting the possibility and relevance of developing servant leadership among educators.

Themes were identified and refined into categories to give a synthesis of the concept of servant leadership in the public sector literature ( Table 4). The content analysis of this article revealed second-order themes (N=32), which were eventually split into seven categories (“Other Oriented”, “Community Vision”, “Relationship Moderator”, “Trust with Empowerment”, “Professional Convincible”, “Moral Model”, “Self-regulated”). These categories were thought to describe servant leadership in the public sector research examined.

In addition to the self- and follower-assessment methodologies indicated in the previous study, servant leadership qualities are measured. ^{69– 73} Most empirical studies on servant leadership in the public sector rely on follower assessment. Individual studies have also used leader self-assessment approaches. ^{96– 99}

Table 5 lists the appropriate single-perspective assessment measures in the last six years. Most studies choose to evaluate from followers, with the global construct of servant leadership (SL-7) scale developed by Liden et al. (2015) being the most popular among researchers (32.4%), ¹¹¹ followed by Ehrhart’s 7 Dimension scale, which has been used in 24.3% of studies The Servant Leadership Survey (SLS) created by Van Dierendonck and Nuijten (2011) is slightly less popular (16.2%). ²⁵

According to Table 6, servant leadership theory has been completely utilised (25.5% usage), manifesting a beneficial impact generally. Social exchange theory and social learning theory have been frequently employed to explain the mediating link associated with servant leadership conduct (15.7% and 13.7%, respectively). The moderating relationship is extensively explained using resource conservation theory (5.9% usage). Simultaneously, self-determination theory is frequently used to describe the impact of servant leadership on subordinate attitudes and actions.

Based on antecedents, mediating processes, results, and boundary conditions, this research develops a nomological network for a sample of quantitative servant-leadership studies in the public sector from 2019 till now. The nomological network depicts factors linked to employees (e.g., voice behaviour), teams (e.g., collaboration), leaders (e.g., perceived leadership effectiveness), and organisations. Arrows show the direction of the link between the variables under consideration. Furthermore, (+) and (-) indications indicate whether a positive or negative association was discovered in the public sector-specific quantitative studies analysed (Details illustrated in Figure 2).

According to this review, the factors that induce the formation of servant leadership can be summarised as personal experience (e.g., position, years of experience) ¹⁴⁰ and organisational conditions (e.g., green human resource management practices, corporate social responsibility, collaborative atmosphere). ^{141– 143} However, there has been little research on the leader-related origins of servant leadership in the public sector over the last six years.

In the last six years, research has tended to verify mediating elements at the individual employee level (23 articles), with little exploration of mediating variables at the leader level (2 articles) and the organisational level (2 articles). Five studies have proven that servant leaders in the public sector improve employee performance through Public Service Motivation ^{120, 137} or organisational factors. Second, servant leaders in the public sector improve employee performance through job satisfaction ^{132, 137} and volunteer retention ¹³⁶ ; and suppress organisational deviant behaviour ⁷⁸ through Trust in the Leader and improve employee performance ¹²⁹ and organisational citizenship behaviour. ⁷⁰

Six years ago, research tended to verify the positive impact of servant leadership through leader empowerment, ¹⁴⁴ environmental protection-related green perceived organisational support, ⁷⁴ and organisational identification. ^{145, 146} However, research in the last six years has focused on verifying the impact of servant leadership through psychological interactions such as Prosocial Values Motives, ⁷³ Emotion Regulation, ⁹⁷ and Psychological Ownership. ¹²²

Like prior studies, research lately has underlined that employee-related psychological empowerment and prosocial motivation are moderating elements that affect the effectiveness of servant leadership. ^{129, 147} Servant leadership has a greater impact on employee performance when subordinates are more psychologically empowered and motivated. ^{115, 148}

Unlike previous research, research has proven new moderating variables from the organisational level, ^{116, 139, 146} Research lately has confirmed the positive moderating effect of Performance-Oriented Climate on servant leadership. ¹¹⁶ Servant leadership can reduce the inhibitory moderating effect of Perceived Organizational Politics (POP), ⁷⁰ bolstering the credibility of introducing servant leadership in the public sector. Besides, researchers have innovatively explored the moderating effect of leader-level characteristics, such as the span of supervision negatively moderating servant leadership’s effectiveness. ¹³²

According to this review, the deployment of servant leadership in the public sector over the last six years has generally produced benefits at the personnel and organisational levels within the organisational behaviour domain. ^{71, 72, 75, 77, 97, 112, 114, 116– 118, 121, 122, 130, 133– 136, 138, 139}

At the organisational level, all studies in this review validated the importance of servant leadership in fostering a prosocial environment. ^{96, 98, 116, 123, 129} At the personnel level, only one article found a weak negative link between servant leadership and employee performance, contradicting the favourable relationship observed. ¹²⁰

In contrast to previous work, the last six years have preferred the influence of servant leadership on employees’ extra-role intentions. ¹¹⁹ For example, ‘Rule Breaking’ Behaviours ^{112, 124} and Proactive Service Behaviour (PSB). ¹²⁷ Furthermore, this review discovered that servant leadership impairs employee deviance, ¹²⁸ cognitive uncertainty ¹³¹ and turnover Intention. ¹²⁵

Firstly, based on this review’s results, rather than creating a universal definition, existing qualitative research on servant leadership is saturated in uncovering servant leaders’ competence. ^{81, 97, 125} Besides, determining the cross-cultural adaptability of servant leaders is a difficult task. ^{20, 35, 57, 78} Further research is needed to generate a uniform definition of servant leadership and determine if servant leadership may have a good impact in diverse cultural contexts, as well as the cultural traits and differential employee acceptance that limit servant leadership’s positive function. ⁹⁸

To tackle with the above issues, more qualitative research is encouraged. Firstly, qualitative research is essential for theory building. ^{79, 80} Qualitative research delves deeply into the experiences, perceptions, and meanings of servant leadership, providing detailed description that quantitative methods might overlook. ^{81, 82, 83} Secondly, servant leadership can vary significantly across different organizational and cultural contexts. ^{25, 26, 44, 57} Qualitative methods allow researchers to capture these contextual differences and understand how SL manifests uniquely in each setting. ^{81, 83, 85} Therefore, by exploring new areas and uncovering underlying mechanisms, qualitative studies can contribute to the development of robust theories of servant leadership. ¹⁵

Secondly, according to the summary of the nomological network in this review ( Figure 2), future research should investigate the specific causes of servant leadership to better understand how to become servant leaders. ¹¹⁴ Future studies can also discover servant leadership’s leader-related outcomes, which are underexplored contemporarily. ^{94, 97} While supplementing the nomological network, future research needs to avoid hypothesis testing bias. ^{138, 142, 147}

To close this research gap, more mixed methodologies could be used. On the one hand, utilising both qualitative and quantitative data enables triangulation, which enhances the validity and reliability of the research findings. ^{87, 88} It ensures that the results are not biased by the limitations inherent in a single methodological approach. ⁸⁹ On the other hand, mixed methods allow for both the exploration of new concepts and the confirmation of existing theories. ^{90, 91} Specifically, qualitative data can uncover new dimensions of servant leadership, while quantitative data can test these dimensions across larger samples. ⁹²

Thirdly, as for the measurement of servant leadership, to avoid lengthy scales in data collection, future studies can continuously streamline existing scales or design more refined ones. ^{75, 77, 107, 120, 122, 126, 142} Moreover, according to what has been found in this review, most empirical studies rely on follower assessment. ¹⁵³ Future studies could try to test the efficacy of the leader’s self-evaluation of servant leadership traits. ^{96– 99, 143} Specifically, customising role-specific and context-specific measurements ensures higher validity and reliability of the assessments.

Regarding the role-specific one, various leadership kinds (e.g., non-government organisation, government, and private sector leaders) and levels (e.g., top executives, middle managers, and frontline supervisors) may demonstrate servant leadership in different ways. ^{100, 101} It is important to design measurement tools that precisely capture these differences. Regarding the context-specific one, a leader’s role might influence the behaviours and outcomes of servant leadership. ¹⁵⁴ Government leaders may prioritize public accountability and openness, whereas leaders of non-governmental organisations may prioritise community service and advocacy. ^{102, 103} Customised scales can therefore make it possible to assess the influence of servant leadership on different organisational outcomes more accurately.

As for the research context, future research can detect more servant leadership applications within non-government organisations (NGOs), rather than government and private sectors. Studying servant leadership in NGO leaders can provide insights into how servant leadership principles are applied in these unique settings. NGOs operate in a context distinct from government and private sectors, often with a stronger focus on community service, advocacy, and social justice. ^{104, 105} Given NGOs’ mission-driven nature, servant leadership may be particularly relevant and prevalent in this sector. ¹⁰⁶ Future research can explore how servant leadership contributes to achieving organisational goals, stakeholder satisfaction, and social impact.

As for the research domain, while servant leadership’s impact on organisational behaviour (OB) is well-documented, its influence on ESG (Environmental, Social, and Governance) performance is less explored. ^{96, 98, 112, 119, 125} Understanding how servant leadership contributes to ESG can provide a more holistic view of its functions. ESG performance is increasingly critical for organisational sustainability and reputation. ¹⁰⁷ Servant leadership aligns well with the principles of sustainability and ethical leadership, which are in line with the ESG’s missions. ¹⁰⁸ Examining its effect on ESG performance can, on the one hand, demonstrate how servant leaders encourage social responsibility, sustainable practices, and sound governance in their organisations. ^{109, 110} On the other side, it can show how servant leaders add value for a wider range of stakeholders, such as workers, communities, and the environment, supporting the organisation’s long-term sustainability and moral standing. ^{108, 122}

Moreover, as for the theoretical base, future studies can expand on social exchange theory to better explain servant leadership. ⁷⁵ At the same time, diverse theoretical viewpoints can be integrated to deepen the theoretical meaning of servant leadership. ⁹⁷ Finally, this systematic review does have some limitations. This review’s search was confined to journal articles published in six electronic databases over the last six years, which constrained the findings of the servant leadership phenomena in the public sector. Other relevant servant leadership publications available in other internet databases, such as grey literature, dissertations, and other unpublished projects (e.g., internal research projects), can provide more compelling reasons for servant leadership theory in the public sector. Future scholars can broaden the scope of their review to include additional fields.

The importance of public-sector decision-makers influences whether they receive servant leadership training. ¹⁵⁵ The persistent positive link discovered between servant leadership and valued outcomes provides solid evidence of nurturing servant leadership in the public sector. ^{66, 118, 129} Therefore, decision-makers could establish servant leadership training programs, which can foster a favourable organisational atmosphere that allows people to go beyond their assigned daily roles. ¹¹⁶ Based on this review’s findings, it is recommended that the public sector should focus on the following seven areas of servant leadership training: “Other Oriented”, “Community Vision”, “Relationship Moderator”, “Trust with Empowerment”, “Professional Convincible”, “Moral Model” and “Self-regulated”).

Although servant leadership relates to beneficial outcomes in the public sector, practitioners should be aware that it is difficult to implement successfully. ²⁶ Bayram and Zoubi (2020) discovered that servant leadership has a varied impact on staff performance in Jordan’s customs service. ¹²⁰ Demissie et al. (2024) and Khattak & O’Connor (2020) discovered a trade-off between servant leadership and Perceived Organisational Politics. ^{21, 70, 113} Simultaneously, the scope of leadership will limit servant leaders’ managerial energy and effectiveness. ¹³² Therefore, practitioners need to be constantly alerted to the dynamics of servant leadership implementation.

This Systematic review adheres to the PRISMA guidelines ( https://www.equator-network.org/reporting-guidelines/prisma/).

https://doi.org/10.6084/m9.figshare.27902247.

Data are available under the terms of the Creative Commons Zero “No rights reserved” data waiver (CC0 1.0 Public domain dedication).

Citation ^159: HIZAM-HANAFIAH, MOHD; LI, XIJIN (2024). PRISMA Checklist and Flow Diagram for “Systematic literature review: Servant leadership in public sectors”. figshare. Dataset. https://doi.org/10.6084/m9.figshare.27902247