Globally, there is an increasing need for human resource management optimisation to enhance management performance because organisations face economic difficulties and complex political situations which impact both public and private sectors (Rafaqat et al., 2022). The public sector faces a particularly difficult challenge as it is forced to operate in a complex institutional context that requires not only efficiency but also compliance with regulations. Recruitment, as a core function of human resource management, is increasingly viewed as a strategic tool that helps organisations to obtain talent that can accelerate the level of organisational effectiveness (Hur-Yagba, 2021). This is particularly true in situations where the level of service delivery is directly influenced by human capital quality, where resources are limited (Ahiawodzi & Kumah, 2024; Pokhrel, 2023). The shift towards e-recruitment has intensified this dynamic: while digital platforms widen the geographic reach of vacancy notices and accelerate screening, they simultaneously risk excluding candidates who are not digitally connected, thereby narrowing the talent pool that public sector organisations are constitutionally obliged to draw from. Against this backdrop, workforce diversity has been gradually transformed into a strategic tool that serves both as a norm and as a competitive advantage, based on its acknowledgement, which brings benefits such as driving innovation, improving decision-making processes and boosting legitimacy among stakeholders (Adawiah & Putra, 2024; Benabou et al., 2024).

While increasing scholarly research appears focused on the effect of recruitment practices and workforce diversity on organisational performance as separate constructs, very few have been conducted to understand the amalgamation of these two factors on the effectiveness of the public sector, and in the context of e-recruitment. The seminal study of Subedi and Bhandari (2024) investigated how recruitment and selection practices influence employee performance in Nepalese public institutions. Although the findings revealed that structured recruitment processes significantly improve service delivery, their study did not consider the role of diversity in the nexus. Similarly, Davoudzadehmoghaddam et al. (2024) examined how diversity management practices shape organisational outcomes in a multicultural workplace; however, their analysis treated recruitment as a background variable rather than a strategic lever. In the African context, Ahiawodzi and Kumah (2024) explored the link between human resource practices and public sector performance in Ghana, while Awolaja et al. (2025) focused on federal character compliance in Nigerian agencies without empirically testing how it interacts with recruitment outcomes. Studies that do address e-recruitment, such as Adawiah and Putra (2024), Benabou et al. (2024) and Zuhriatusobah et al. (2025), concentrated on candidate engagement, employer branding and the digitally connected segments of the labour force, leaving the experiences of non-tech-savvy applicants and the moderating role of workforce diversity largely unaddressed. Collectively, these studies advance understanding of either recruitment or diversity in isolation, but none have empirically modelled the interaction between the two, particularly where e-recruitment is the dominant external method and where digital exclusion is a salient diversity concern. This study fills these interrelated gaps by empirically modelling the moderating effect of workforce diversity, conceptualised to include digital access and digital literacy diversity, on the relationship between e-recruitment based practices and organisational effectiveness. The analysis is deliberately situated in the Nigerian public sector, where the constitutional federal character provision renders diversity a binding institutional requirement rather than a voluntary organisational choice, thereby generating evidence-based guidance on how public organisations in developing economies can harness e-recruitment without undermining inclusive representation. This research gap is particularly obvious in the public sector organisations of developing countries (such as Nigeria), where institutional pressures, resource constraints and diversity mandates interact in a complex way that can either facilitate or hamper the impact of recruitment practices.

The Nigerian public sector offers an interesting case study for research on the combination of factors affecting the performance of its organisations. The constitutionally enshrined federal character provision effectively changes diversity from being just a matter of choice to becoming an established practice (Awolaja et al., 2025; Ekhomeh et al., 2022; Obamiro et al., 2019). This institutional set-up thus, constitutes a mechanism through which organisations can be required to manage merit-based external hiring and still maintain a diverse workforce. Nonetheless, the extent to which workforce diversity moderates the effect of external recruitment on organisational effectiveness is still an unanswered question in this scenario, hence, the lack of both the development of theoretical insights and practical solutions for the efficient use of resources. Therefore, this study is critical for public sector managers seeking a deep understanding of how workforce diversity drives the recruitment and performance relationship.

This research examines the moderating effect of workforce diversity on the relationship between recruitment practices and organisational performance in the Nigerian public sector, with particular emphasis on external recruitment methods. The study aims to provide evidence-based insights into these dynamics and contribute to the existing body of academic knowledge on strategic human resource management in developing-economy contexts. However, the objectives of this study are to:

The study is expected to add theoretical, practical and strategic value to the existing body of knowledge. Theoretically, human capital resource would be better understood by examining how external recruitment methods and workforce diversity interact to shape organisational outcomes, particularly in public sector contexts where diversity mandates coexist with performance imperatives. Practically, administrators in Nigeria’s public sector would be informed on how best to invest in resource recruitment, and, strategically, they would gain valuable insights on how to integrate federal character compliance into their goals in resource-constrained settings.

The remaining parts of the article are structured into five sections. Section two reviews the literature, covering, external recruitment methods (with emphasis on e-recruitment), workforce diversity and organisational effectiveness, the empirical review and hypotheses formulation. Section three details the research design, sample, data collection instrument and analytical techniques. Section four presents the results, including descriptive statistics, measurement model assessment and tests of direct and moderating effects. Section five discusses the findings against existing literature and the theoretical framework, as well as the limitations and recommendations. Section six concludes the study, presenting its practical implications.

Modern scientific studies have identified considerable evidence supporting the relationship between external recruitment methods and organisational outcomes. Musaba et al. (2024) conducted an extensive study to evaluate the efficiency of external recruitment strategies. According to the study, sophisticated external recruitment strategies are vital in improving the quality of employees as well as the competitiveness of the organisation. The study also underscored the fact that organisations using multiple external recruitment strategies have better employee acquisition efficiency compared to those using traditional external recruitment strategies. Moreover, Zuhriatusobah et al. (2025) examined the impact of e-recruitment strategies, employer branding and compensation on the job application interest of Generation Z employees. According to the study, e-recruitment strategies are vital in improving the attractiveness of the organisation to younger age groups in the labour market. The study also identified the fact that e-recruitment strategies help organisations access technologically advanced employees.

In their study, Aldhuhoori et al. (2022) aimed to determine the effects of recruitment, selection and training approaches on the performance of employees in the construction sector. The findings indicate that the sophistication of the recruitment process in an organisation has a very significant positive effect on the performance of employees. It was also found in the study that organisations with an established system of external recruitment exhibited improved quality in terms of their workforce, as well as improved productivity in their organisational set-up.

Adawiah and Putra (2024) determined the effects of implementing an electronic recruitment process on the credibility of companies, as well as the efficiency and transparency of the process from the applicants’ point of view. The authors found that an electronic recruitment process improved the credibility of companies as perceived by applicants while enhancing the efficiency and transparency of the process.

Similar research by Benabou et al. (2024) studied the effect of e-recruitment on recruiter–candidate engagement within African organisations. The study found that organisations where e-recruitment tools were employed reported an increase in the number of responding candidates, quality communication and quality candidate experience compared to those that did not employ e-recruitment tools. Also, the research by Townes et al. (2025) on employee selection within organisations in South Africa concluded that organisations where advanced external recruitment methods had been employed showed a significant outcome in the enhancement of person-organisation fit, thereby improving employee retention relative to those that did not use advanced recruitment practices.

Beyond e-recruitment, organisations also rely on a range of other external recruitment strategies that remain particularly relevant in developing economies, where digital infrastructure and internet access are limited. These include the use of private and public employment agencies, walk-in applications, print and broadcast media advertisements (newspapers, radio and community bulletin boards), employee referrals, campus and graduate recruitment drives, professional association networks, and, in the public sector, recruitment notices issued through the Federal Civil Service Commission and state-level service commissions (Aldhuhoori et al., 2022; Musaba et al., 2024; Townes et al., 2025). Each of these methods offers a distinct value proposition: employee referrals tend to yield candidates with better person–organisation fit and lower turnover, employment agencies provide pre-screened pools that reduce search costs, while print and broadcast advertisements remain the most inclusive channel for reaching applicants in rural and semi-urban communities.

Importantly, the focus on e-recruitment in recent literature risks excluding qualified candidates who lack reliable access to digital technology, stable internet connectivity, or the digital literacy required to navigate online application portals. In Nigeria and similar developing-economy contexts, where a substantial proportion of the working-age population resides in areas with limited Internet connectivity, an over-reliance on e-recruitment could narrow the talent pool, deepen urban–rural inequalities in access to public sector employment, and undermine the federal character mandate that requires equitable representation across geopolitical zones. Consequently, effective external recruitment in the Nigerian public sector should be understood as a multi-channel strategy that blends digital platforms with traditional, offline methods, thereby ensuring that the benefits of advanced recruitment practices are not confined to digitally privileged segments of the labour market.

Empirical studies on the influence of workforce diversity on organisational performance (through effectiveness) have shown consistent findings on positive relationships between diversity and various organisational outcomes. Nzimande et al. (2025) assessed how recruitment, selection and retention methods drive workforce diversity in South African public organisations. The research demonstrated that organisations can achieve better performance results through their diversity programmes when these programmes are implemented together with their effective human resource management systems. The research showed that organisations which implemented diverse workforces achieved better decision-making processes, stakeholder engagement and service delivery outcomes.

Subedi and Bhandari (2024) examined the effects of workforce diversity in Nepali commercial banks, which provided quantitative empirical support for the relationships between various aspects of workforce diversity, such as differences in gender, age, ethnicity, educational background and aspects of organisational effectiveness. The results of this study clearly showed a positive correlation between workforce diversity, in various aspects, and aspects of organisational effectiveness.

The focus of Ahiawodzi and Kumah (2024) was on the management of diversity in the workplace in the context of effective organisational arrangements required for global organisations. They found that the most important change in organisational effectiveness and performance was that diversity management practices were very efficient. The research emphasised that diversity effects were contingent upon effective management of diversity in such a manner that it provided significant advantages while limiting any possible coordination issues in diversity management. Pokhrel (2023) studied diversity variables together with organisational success indicators which proved that workforce diversity management positively affected success indicators through three specific areas of innovation, market development and competitive advantage.

Davoudzadehmoghaddam et al. (2024) carried out a systematic review of literature on workforce diversity, particularly on its impact on organisation-level outcomes and diversity management practices. The systematic review of literature on workforce diversity discovered that its beneficial effects on organisational results work through multiple channels which include better information processing abilities, increased problem-solving capacity and higher organisational credibility with different stakeholder groups. The review of various empirical studies on workforce diversity resulted in the conclusion that it positively impacts organisation-level outcomes when it is complemented by corresponding diversity management practices.

The research conducted by Ekhomeh et al. (2022) focused on workforce diversity and employee performance among Nigerian domestic systemically important banks. The results demonstrate a strong positive relationship between diversity and employee performance. Also, Awolaja et al. (2025) investigated how workforce diversity affects employee performance at selected fast food centres in Osun State, Nigeria. The study proved that various levels of workforce diversity within an organisation directly benefited employees through improved job performance.

The seminal study of Liu et al. (2023) found that organisational diversity effects depend on human resource management system performance because inclusive human resource systems convert potential diversity impacts into organisational advantages. The study implies that diversity in organisations does not simply function as an organisational feature or construct but as an organisational context in its own right that affects organisational processes in conjunction with other organisational systems or processes.

Rafaqat et al. (2022) studied how workforce diversity influences organisational performance through a systematic literature review. They synthesised a series of research papers that empirically investigated the impact of workforce diversity on employee performance to provide clearer insights into the discussions. The literature review indicated that the influence of diversity on organisational performance is significant, though it can vary greatly depending on the organisational context, thus, emphasising the need to consider contextual factors that can influence the relationship between diversity and organisational performance. It is, however, important to note that limited research has been conducted to justify the influence of diversity on the effectiveness of certain human resource management practices, a significant research gap that needs to be filled.

Despite documented evidence on the effectiveness of sophisticated external recruitment methods and workforce diversity on organisational effectiveness, empirical research on these factors’ combined effects is limited, especially within African public sectors, where constitutional diversity requirements may differ from those found within voluntary diversity settings. Even though research has shown that both external recruitment methods and workforce diversity independently enhance organisational effectiveness (Adawiah & Putra, 2024; Aldhuhoori et al., 2022; Benabou et al., 2024; Musaba et al., 2024; Townes et al., 2025; Zuhriatusobah et al., 2025) and that workforce diversity is positively correlated with organisational effectiveness (Ahiawodzi & Kumah, 2024; Davoudzadehmoghaddam et al., 2024; Nzimande et al., 2025; Pokhrel, 2023; Subedi & Bhandari, 2024), limited research has empirically studied their combined effects on organisational effectiveness.

Liu et al. (2023) and Rafaqat et al. (2022) recognised that diversity’s effectiveness is likely dependent on the quality of human resource management within an organisation, but did not empirically investigate diversity’s effectiveness, especially that of diversity as an intervening factor for the effectiveness of specific human resource practices’. Therefore, this study examines the interactive effects of external recruitment methods and workforce diversity on organisational effectiveness in Nigerian public sector organisations. Consequently, this study is guided by the following hypotheses:

This study adopts a positivist philosophical stance, which accepts the existence of objective reality and considers observation, measurement and analysis as essential research methods. The researchers conducted a descriptive cross-sectional survey to collate data about external recruitment methods, workforce diversity and organisational performance in six public sectors across Nigeria.

This section explains the different methodological steps taken by the study to achieve the research purpose and objectives.

The research population comprised 20 264 employees drawn from six federal government organisations in Nigeria, specifically from the telecommunication, finance, health, education, oil and gas and law enforcement sectors. These organisations were purposively selected based on their organisational size, diversity of workforce composition and strategic relevance to national development in Nigeria. A proportional stratified sampling technique was utilised to ensure that the sample drawn was an adequate representation of the target population in terms of organisational affiliation, cadre of staff and departmental spread.

To determine the appropriate sample size, the Krejcie and Morgan’s (1970) sample size determination table was employed, yielding a recommended sample size of 377 participants. Accordingly, questionnaires were distributed to 377 employees across the six organisations, with the number allocated to each organisation calculated proportionally based on its share of the total population. This proportional allocation ensured that no single organisation dominated the sample and that the distribution reflected the relative size of each organisation within the overall study population.

The study recruited participants from various organisational levels (junior, middle-level and senior staff) to ensure a wide and representative sample of views on recruitment, workforce diversity and organisational effectiveness. The recruitment of participants was facilitated through collaboration with the Human Resource personnel of each organisation, who assisted in identifying eligible employees and coordinating questionnaire distribution. Eligibility criteria required that participants be full-time, permanent employees who had been with their respective organisation for a minimum of 1 year, ensuring that respondents possessed adequate familiarity with organisational practices to provide informed responses.

Data collection resulted in 366 valid responses, representing a 97.1% response rate, which is considered highly satisfactory for survey-based organisational research (Baruch & Holtom, 2008). The final analytical sample therefore comprised 366 employees distributed across the six public sector organisations proportional to the size of each organisation.

Reflective multi-item measures were used to collect data on all constructs. The existing measures, which successfully passed testing in multiple organisational environments, served as the foundation for developing the measurements, which researchers modified to make them suitable for use in Nigerian public sector organisations. All measures used a 5-point Likert scale.

External Recruitment Methods (ERP): Measured using the 9-item External Recruitment Methods (ERP) scale, which assesses the success of external recruitment channels and their usage, was developed according to Breaugh (2008), Acikgoz (2019) and Nikolaou (2014). Pilot test reliability was α = 0.91.

Workforce Diversity (WD): Measured using an eight-item scale, derived from Nzimande et al. (2025), Bazana and Reddy (2021) and Musakuro (2022), that measures perceptions of workforce demographic diversity along various dimensions (α = 0.88, pilot reliability).

Organisational Effectiveness (OE): Measured using an eight-item scale adapted from Nzimande et al. (2025), Louw (2013) and Abiwu and Martins (2024), measuring perceived organisational effectiveness (pilot reliability: α = 0.92).

Data Collection: The data were collected in November and December 2025. Questionnaires were disseminated electronically using Google Forms to participating employees of the selected public sector organisations, specifically to those with access to their organisation’s email. Physical structured questionnaires were also disseminated to employees who work in field offices or have no access to internet connectivity. This involved working with the respective organisation’s Human Resource Departments. There were various procedural interventions to control the risk of Common Method Bias. Also, the single-factor test by Harman proved that the validity of the study was not compromised by Common Method Bias (Podsakoff et al., 2003).

Partial least squares-structural equation modelling (PLS-SEM) was used as the main analytical method in this study since the technique allows for investigating the complex relationships with both direct and moderating effects concurrently (Aiken & West, 1991; Hair et al., 2022; Kline, 2016). The analysis of the research data was carried out with SmartPLS 4.0 software (Ringle et al., 2022) and in line with the latest PLS-SEM standards (Aguinis et al., 2005; Hair et al., 2022; Henseler et al., 2015).

Ethical clearance to conduct this study was obtained from the Nile University of Nigeria Academic Assurance Committee (Ref. No. 014/2026).

Informed Consent: Before participating, each respondent gave their written informed consent. Also, in the questionnaire preambles, the purpose of the study, the rights of the participants, confidentiality, and the principles of voluntary participation had been clearly indicated. No personally identifying information was collected in the study, as the demographics collected were at categorical levels that made it impossible to identify individual participants. No incentive was offered to ensure that the responses obtained were authentic and voluntary.

Data Protection: The collected data were safely stored through encrypted and password-protected cloud storage platforms that were limited to access by members of the research team only. This ensured full compliance with the relevant regulatory institution on data protection and the research ethical principles. In terms of electronic storage, encrypted storage through AES-256 with multi-factor access control was used. Physical questionnaires were stored safely before inputting the data and subsequent destruction.

The significant positive relationship between external recruitment methods and organisational effectiveness (β = 0.337, f² = 0.86) further validates the significance of e-recruitment-based external recruitment practices in the performance of the public sector. These findings lend credence to the theory of strategic human resource management by Delery and Roumpi (2017). The research demonstrates that organisations need human resources to develop their essential capabilities because human resources determine the quality of their workforce.

Public sectors that use multiple external recruitment sources such as the internet, social media sites, employment agencies and associations tend to access higher quality and quantity of potential employees compared to those who use fewer traditional recruitment methods (Acikgoz, 2019; Breaugh, 2008; Breaugh & Starke, 2000). Recruitment technologies also cover a larger geographic area through the use of the internet to reach the six geopolitical zones of the country for the purpose of compliance with the principle of federal character. Social media sites also offer the opportunity to reach the youth who are technology-savvy and are essential for the operation of agencies in the technology age. Employment agencies offer expert advice for the recruitment of employees who possess scarce skills necessary for certain positions.

The findings are commensurate with recent research on the positive effects of e-recruitment on organisational attractiveness (Ali et al., 2021), candidates’ engagement (Benabou et al., 2024), efficiency and transparency of recruitment processes (Adawiah & Putra, 2024) and workforce quality (Aldhuhoori et al., 2022; Musaba et al., 2024). This study builds on previous research on effectiveness rather than on recruitment metrics, thus revealing recruitment’s ultimate influence on organisational performance within Nigerian public organisations.

The exceptionally high positive association between workforce diversity and organisational effectiveness (β = 0.930, f² = 6.52) is the most remarkable finding of this study. The association far outstrips conventional criteria for an effect size and appears to indicate that workforce diversity is a determinant of organisational effectiveness in Nigerian public sector organisations. Under the constitutional framework of the Nigerian federal character principle, workforce diversity is likely to be mediated by a number of mechanisms simultaneously: legitimacy and/or trust mechanisms, quality of services mechanisms, mechanisms for decision-making and innovation (Delery & Roumpi, 2017) and organisational quality-signalling mechanisms. These outcomes support information processing-related theoretical perspectives, while also extending this literature into diversity in institutions. More recently, a study of public sectors in South Africa found that diversity’s organisational outcomes were also positive (Nzimande et al., 2025), albeit at a significantly weaker magnitude, perhaps due to the salience of a federal system in Nigeria that heightens diversity-effectiveness linkages.

The substantial positive moderation result (β = 0.700, f² = 0.96) represents this study’s most important theoretical innovation in showing that external recruitment methods and organisational effectiveness vary in a heterogeneous fashion depending upon diversity contexts. Results of simple slopes indicated that sophistication in external recruitment translates to effectiveness gains 6.4 times higher in high-diversity than in low-diversity agencies. Three theoretical accounts of observed synergy effects exist: network amplification (Carpentier et al., 2019), signalling effects of employer brand (Highhouse et al., 2007; Ryan et al., 2005) and professionalisation of external recruitment due to organisational pressure (Nzimande et al., 2025). The result has profound implications for dominant universalistic ‘best practice’ views in human resource management theory in supporting alternative contingency theory approaches to understanding human resource practice effectiveness in a fashion contingent upon organisational contexts (Delery & Roumpi, 2017).