Human resource development and turnover intention: organizational commitment ’ s role as a mediating variable

Purpose – The purpose of this paper is to examine the effect of human resource development on turnover intention through the mediating role of organizational commitment. Design/methodology/approach – Thispaperusedaquantitativeresearchdesign.Datawerecollectedfrom 204 flight attendants employees working at Royal Jordanian Airlines Company using an email survey questionnaire. Structural equation modeling (SEM) was adopted to test the hypothesized model. Findings – The results assure positive effect of human resource development (HRD) on organizational commitment. Negative effect of both HRD and organizational commitment to turnover intention is observed. The results also confirm that the effect of HRD on turnover intention is negatively mediated by organizational commitment. Originality/value – This research paper extends the literature by empirically adducing evidence that organizational commitment negatively mediated the effect of human resource development on turnover intention of the airlines in Jordan.


Introduction
Today, a shortage of talented flight attendants, low retention rates and high turnover rates persistently challenge aviation organizations worldwide. In Jordan, the retention of qualified flight attendants has become one of the main challenges for aviation organizations. Failing to retain talented flight attendants has caused increased turnover rates in aviation organizations. The literature evidence suggests that turnover rate increases can increase organizational costs (Bhatti et al., 2016;Rawashdeh and Tamimi, 2019) monetary and nonmonetary. On the one hand, recruiting and hiring the best new applicants incurs monetary costs (Haider et al., 2015).

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On the other hand, nonmonetary costs include losing skilled, knowledgeable employees to other organizations (Nasurdin et al., 2018). Turnover rate increases have led aviation organizations to bear additional charges because of the continuous hiring of new flight attendants. So, aviation organizations must seek ways to reduce turnover intentions (TOI) among their workers and increase their retention rates for highly skilled and well-trained flight attendants. Organizational commitment (ORC) has been a popular and well-documented predictor of turnover among employees (Kadiresan et al., 2015;Bhatti et al., 2016). But recently, scholars echoed the possible implications of human resource development (HRD) for ORC, turnover and related work outcomes (Kareem and Hussein, 2019;Nawaz and Pangil, 2016). HRD is a framework designed to help employees develop and gain new skills, knowledge and competencies that subsequently contribute to organizational effectiveness. Specifically, HRD bundles activities such as training development, compensation, career enhancement, performance evaluations and firm development together to enhance organizational effectiveness both at the individual and organizational levels (McLagan, 1989). So, HRD and ORC should be a part of the model to predict TOI. HRD has significantly influenced TOI (directly or indirectly) through ORC (Nawaz and Pangil, 2016). Kadiresan et al. (2015) used a sample from the manufacturing industry, and Juhdi et al. (2013) used employees working in the insurance and finance industries, banks and higher educational institutions. But little research has been conducted, and its geographical scope remains limited. It requires supplementation with additional analysis in other regions, industries (i.e. aviation) and contexts (i.e. developing countries), as the results would provide valuable guidance for managerial practices. Social exchange theory (SET) supports the intervening role of ORC on the causal link between HRD and TOI, as noted by Blau (1964), who postulated that individuals enter a relationship with a firm in exchange for benefits (Jawaad et al., 2019;De Juana-Espinosa and Rakowska, 2018). According to this theory, when employees perceive their relationship or bond with their hiring organization as positive, they increase in commitment to the firm, becoming less inclined to leave the organization (Cherif, 2020). Shehawy et al. (2018) examined the determinants of airline workers' job embeddedness in Egypt. Choi and Jang (2018) conducted a study on the job anxiety, TOI and job satisfaction of aviation security employees. Satardien et al. (2019) scrutinized the nexus between perceived organizational support, ORC and TOI among South African aviation industry employees. Building on SET, Chung and Jeon (2020) examined the nexus between job satisfaction and TOI in the airline industry. Alola and Alafeshat (2021) researched human resource practices' impact on employee engagement in the Jordanian airline industry.
Interestingly, the extant literature also denotes that past research has focused on investigating various aviation careers, such as load control agents and support staff (Satardien et al., 2019), aviation security search employees (Choi and Jang, 2018) and cabin attendants (Cho and Ko, 2010). But the current paper focuses on Royal Jordanian Airlines' flight attendants to gauge for variations. The extant literature suggests a lack of research on the roles of HRD and ORC in predicting TOI in a developing country's aviation industry. This paper's objective is threefold. It first aims to investigate HRD's impact on ORC and TOI. Second, it examines the ORC's influence on TOI. Third, it predicts HRD's impact on TOI through the mediating role of ORC. The study's findings will help airline managers and policymakers develop appropriate strategies to enhance HRD, stimulating flight attendants' ORC and minimizing their intentions to resign.
This study consists of five sections. The current section provides a brief overview and the motivations and objectives of the study. Section 2 provides the study model and proposed hypotheses. Section 3 describes the sampling, data collection tools and research instruments. Section 4 presents the research findings. The final section offers the key results and implications for aviation companies, followed by the limitations and future research prescriptions.
2. Literature and hypotheses development 2.1 Human resource development HRD is a collection of interrelated internal activities designed to stimulate individuals' skills, knowledge and competencies (Nawaz and Pangil, 2016;Rawashdeh and Karim, 2012). Organizational survival and effectiveness rely substantially on the efficiency of its human capital and activities (Simões et al., 2018;Uma et al., 2017), especially employees' skills and competencies (Ong et al., 2019), which are essential for firms to meet their predetermined goals and objectives (Ana et al., 2019). Possessing qualified, skilled human resources is the most significant capital for firms because human capital impacts and constitutes firms' various resources while being influenced by them (Koç et al., 2014). HRD is concerned with promoting employees' knowledge and capabilities through a series of organized human resource (HR) practices (Kareem and Hussein, 2019). HR practices that work with the organizational strategy focus on creating positive outcomes within a reasonable time (Rafik et al., 2019). Investment in HR practices is a critical source of positive organizational performance, as it enhances employees' motivation, skills, knowledge and ORC, reducing TOI (Kareem and Hussein, 2019). HRD (in this study) comprises three practices, namely, training and development, compensation and performance appraisals, based on Nawaz and Pangil's (2016) study. The most significant HR functions connected with employee TOI are fair compensation criteria, good performance appraisal criteria and training and development. They have been described as the main drivers of employees' intentions to commit to or leave their organizations (Aburumman et al., 2020;Juhdi et al., 2013;Kadiresan et al., 2015).

Human resource development and organizational commitment
ORC is categorized mainly into three forms. Affective commitment reflects an individual's personal connection to and discernment with the hiring organization and their ultimate participation in organizational affairs. Continuance commitment reflects an individual's costbenefit analysis of continuing or terminating employment with the hiring organization. Lastly, normative commitment reflects an individual's sense of obligation to remain with the employer (Norm et al., 2017;Rawashdeh and Tamimi, 2019). HRD should establish a positive work environment to motivate employees to become more committed and productive (Rafik et al., 2019). Effectively implemented HR practices can also stimulate individuals' commitment and performance (Cai et al., 2019). HR practices are considered one of the best predictors used widely to examine employee's ORC (Cherif, 2020). Several studies have been conducted in various countries and contexts. All documented a significant correlation between different HR practices and ORC. For example, Koç et al. (2014) conducted research in Turkish private organizations on HR practices, job satisfaction and ORC and discovered a positive association between the studied variables. In Jordan, Suifan (2015) studied some public and private organizations. His findings indicated a positive, significant relationship between HR practices ("training, person-organization fit, and rewards") and ORC. In their study, Fihla and Chinyamurindi (2018) reported the significant influence of HR practices (hiring and retaining policies, training and development, rewards and performance management) on ORC among South African workers, supporting the conclusions reached by Cherif (2020) and Abdirahman (2015). Accordingly, we propose the following hypothesis: H1. HRD has a positive influence on employees' organizational commitment.

Organizational commitment and turnover intention
ORC is a psychological condition connecting individuals to an organization (Alamri and AL-Duhaim, 2017). ORC is individuals' emotional attachment to their hiring organization that supports their loyalty and reduces their intention to quit (Nawaz and Pangil, 2016). ORC is HRD, ORG and turnover intention denoted as a determinant for higher levels of TOI (Wong and Wong, 2017) because individuals with high levels of ORC are less likely to leave their hiring organizations (Bonds, 2017 H2. Organizational commitment has a negative influence on employees' turnover intention.

Human resource development and turnover intention
HRD is a set of various interrelated HR practices to develop and retain the best, most qualified employees (Rafik et al., 2019). Firms can also direct HR practices toward reducing employee turnover (Nawaz and Pangil, 2016). Firms' effective implementation of HR practices enhances individuals' skills and capabilities and reduces TOI (Mira et al., 2019). Generally, individuals are more likely to remain committed to a firm (rather than quit) when they accept and value HR initiatives such as training and development, compensation and performance assessments (Kadiresan et al., 2015;Nasurdin et al., 2018). Some previous studies have reported that HR practices can influence employee TOI. Ozolina-Ozola (2014) conducted a Latvian study. It demonstrated the significant effect of HR practices ("training, rewards, performance appraisal, internal communication, involvement, equal opportunities, employment security, and prestige") on employees' TOI. Joarder and Sharif's (2011) Bangladesh study noted that HR practices and provisions such as supervisory support, rewards and assurance of job security are strong determinants of TOI. Da Silva and Shinyashiki (2014) concluded that HR practices ("recruitment and selection, benefits, and training and development") are linked significantly to TOI. But compensation, integration and performance are not. Aburummana et al. (2020) (in Jordan) demonstrated that HR practices ("compensation, performance appraisal, promotion, and training and development") negatively impact employees' TOI. Accordingly, we propose the following hypothesis: H3. HRD has a negative influence on employees' turnover intention.

The mediating role of organizational commitment
The present study builds on past research by investigating the role of ORC in the relationship between HRD and TOI. Organizations need to adopt HRD practices leading to ORC. These, in turn, lead to decreased employee TOI (Kadiresan et al., 2015). For example, training, rewards and performance appraisal are effective practices that contribute positively to ORC (Jawaad et al., 2019). ORC has long been considered a valuable factor that can reduce employees' turnover by supporting their commitment to work (Labrague et al., 2018). ORC is negatively related to employee turnover, meaning that when employees are highly committed to the firm, they are less inclined to quit their jobs (Ekhsan, 2019). Most management scholars (e.g. Agarwal and Sajid, 2017;Hung et al., 2018;Rawashdeh and Tamimi, 2019) have confirmed that ORC strongly predicts employee TOI. Similarly, some previous studies have demonstrated ORC's significant impact on the relationship between HR practices and TOI. Nawaz and Pangil (2016) conducted a Pakistani study that found a negative association between HRD factors such as salary, performance appraisal and TOI, and a partial mediating role of ORC on HRD's components (i.e. performance appraisal, promotion, remuneration and career growth) and TOI. In their Malaysian study, Nasurdin et al. (2018) indicated that performance appraisal and compensation are negatively related to TOI and decrease TOI via ORC. Juhdi et al. (2013) reported that the relation between HR practices and TOI is partially mediated by ORC. Kadiresan et al. (2015) documented that a correlation exists between HR practices (such as training and development and performance appraisals) and ORC, which, in turn, contributes to an inverse relationship with employee TOI. Accordingly, we propose this hypothesis: H4. Organizational commitment mediates the association between HRD and turnover intention.

Study instruments
This research adopted a quantitative research design with the aid of a cross-sectional survey.
The items used to measure the research constructs were derived from past studies with appropriate amendments to fit the aviation industry. The research constructs include a predictor variable, HRD; a response variable, TOI; and a mediator variable, ORC. HRD was measured with three dimensions. The training and development dimension was operationalized with a four-item scale borrowed from Tabouli et al. (2016) and Rawashdeh (2018). The performance appraisal dimension was operationalized with a four-item scale borrowed from Chuang and Liao (2010) and Jawaad et al. (2019). And the compensation dimension was operationalized with a four-item scale borrowed from Chuang and Liao (2010) and Rawashdeh and Karim (2012). It included sample items like "The company encourages employees to participate in training programs".
Three types of organizational commitment were measured: affective, continuous and normative. A nine-item scale, derived from Norm et al. (2017) and Rawashdeh and Tamimi (2019), was used to measure organizational commitment. It included sample items like "I would feel guilty if I left my company right now".
Employees' turnover intention was measured with an eight-item scale derived from Lum et al. (1998) and Santoni and Harahap (2018). It included sample items like "The current job does not satisfy my personal needs".
The researchers collected information about the participants such as gender, age, education and work experience. The study measures were based on a five-point Likert scale (strongly disagree 5 1 to strongly agree 5 5).

Respondents' demographic data
Before the survey, the researchers conducted a pilot test with seven participants to ensure the respondents could answer the questions quickly. Then, permission for data collection was obtained from the company's top management. Next, the researchers assured the company's and participants' confidentiality. The employees who participated were told that the data they provided would not be disclosed to third parties or their management. To protect their privacy and confidentiality, we asked them not to disclose any information that could reveal their identity, as per Podsakoff et al.'s (2012) suggestions. As noted earlier, this study's sample comprised flight attendants from Royal Jordanian Airlines. Data were obtained between June and July 2021. According to their human resource department, the company employed over 1,000 flight attendants. A simple random sampling technique was employed. Approximately 300 survey links were sent via email to the target respondents. Finally, 216 useful samples were collected, but some had missing information. So, only 204 valid responses were suitable for analysis, yielding a response rate of 68%. Table 1 shows the respondents' demographic breakdown and distributions.

Data analysis and results
The obtained data were analyzed using a covariance-based SEM technique in IBM SPSS AMOS. The research model fit indices were tested, and then the internal consistency and validity of the constructs were diagnosed. Finally, the hypotheses testing was conducted.

Common method bias
Considering that the current study has a time horizon synonymous with a cross-sectional design, it is susceptible to common method bias (CMB). The test for CMB was executed using Harman's single-factor test, which suggests that the explained variance for any single factor should be less than 50% (Riley et al., 2018). We used IBM SPSS to extract one factor, and the results showed that the total variance explained for the single factor was 40%. This result indicates the current data are not significantly influenced by CMB (Tamura et al., 2019).

Reliability and validity
The average variance extracted (AVE) indicator with a coefficient above 0.50 was utilized to establish convergent validity (Albayrak et al., 2020). Discriminant validity was tested using the square root of AVE values, which should be greater than the correlation coefficients between any pair of the predictor variables (Butt et al., 2021). The results in Table 1 show acceptable values of AVE -0.672, 0.721 and 0.824and acceptable values of discriminant validity, that is, the square root of AVE values exceeded the highest correlation coefficients between constructs (0.541), as can be seen in Table 2. Internal consistency reliability was measured using Cronbach's alpha (α), composite reliability (CR) and McDonald's omega (ω), with a threshold value of 0.70 (Akhtar et al., 2021;Marchena-Gir aldez et al., 2021). The results in Table 1 Table 3, HRD has a significant and positive relationship with ORC (r 5 0.300, ρ < 0.001) and a negative relationship with TOI (r 5 À0.252, ρ < 0.001). ORC has a negative and significant relationship with TOI (r 5 À0.292, ρ < 0.001). In Table 3, the collinearity statistics, as measured by tolerance (Tol) and the variance inflation factor (VIF), indicate that the current data are free from multicollinearity because the tolerance values exceeded 0.4, and the VIF values were less than 2.5 (Adeboye et al., 2014).

Hypotheses testing
The findings illustrated in Table 3 and Figure 2 indicate the direct positive effect of HRD on ORC (β 5 0.311, ρ < 0.001), meaning that a 100% increase in HRD perception by flight attendants will result in a 31.1% increase in ORC. Hence, H1 is supported.
ORC has a direct negative and significant effect on TOI (β 5 À0.271, ρ < 0.001). This effect means that a 100% increase in flight attendants' ORC will result in a 27.1% decrease in TOI. Hence, H2 is supported. HRD has a significant and direct negative influence on employee's TOI (β 5 À0.175, ρ 5 0.046), meaning that a 100% increase in HRD perception by flight attendants will result in a 17.5% decrease in TOI. Hence, H3 is supported. Accordingly, the results demonstrate a negative total effect of HRD on employee's TOI (β 5 À0.259, ρ 5 0.001) and a negative indirect effect of HRD on TOI (β 5 À0.084, ρ 5 0.002), meaning that the impact of HRD on TOI is mediated negatively by ORC. Hence, H4 is supported (see Table 4).

Discussion
This current investigation is motivated by a lack of research exclusively focused on the nexus between HRD, TOI and ORC in the aviation industry and the failure to recognize HRD's implications for ORC and turnover by practitioners. Specifically, this research investigates HRD's effect on flight attendants' TOI through the intervening role of ORC in a developing country context. All the proposed hypothesized associations received empirical support. Discussion of the findings in light of their theoretical and managerial implications appears in the succeeding sections.

Theoretical implications
This study's results make multiple contributions to the body of knowledge in HRD, ORC and TOI. It generates four distinct, valuable implications for theory and research for aviation management literature.
First, HRD has a positive effect on ORC. This effect implies that the employee who perceives HRD availability in the company positively is more interested in continuing to work for the company. Also, this means that Royal Jordanian Airlines has a fair HRD system, one designed to support individuals' commitment. This result proved that HRD factors (training and development, compensation and performance appraisal) have collectively produced high levels of employee commitment. The current finding is not just consistent with Fihla and Chinyamurindi's (2018) claims, which linked HRD with higher levels of ORC. It also complements the relationship between HRD and ORC among flight attendants in a developing country's aviation industry. According to Nawaz and Pangil's (2016) research, HRD can influence employees' attitudes positively, leading to a high level of ORC. Kareem and Hussein (2019) indicate that HRD can provide some benefits, such as the knowledge, skills and ability needed to accomplish one's job, which will increase one's likeliness to stay with the firm.
Second, the result shows that ORC has a negative influence on employees' TOI. Most past studies support this study's finding that ORC negatively affects TOI (Hung et al., 2018;Rawashdeh and Tamimi, 2019;Ekhsan, 2019). Sources of employees' commitment come in various forms, that is,. when employees have strong emotional attachment and identification with their organizations or feel obliged to repay and reciprocate favors conferred by their organizations. They tend to exhibit higher levels of commitment that reduce their inclination to quit (Bonds, 2017;Ekhsan, 2019;Hung et al., 2018;Labrague et al., 2018). The current study has contributed to the literature on this relationship in a developing country's aviation industry and flight attendants' perspectives.
Third, HRD has a negative direct and indirect effect on employee TOI. Employees have career and growth aspirations. HRD practices help fulfill these aspirations by creating a climate of concern, care, fairness and learning and development opportunities. Employees who have a feeling of obligation and attachment to their employer are less prone to engage in TOI. The current finding is consistent with past outcomes. For instance, Nawaz and Pangil (2016) state that investment in HRD can produce high ORC and lower rates of TOI. And the effective implementation of HR practices by firms has been shown to enhance individuals' skills and capabilities, reducing TOI (Mira et al., 2019). The current work studies the presence and texture of the relationship between HRD and TOI in a developing country's aviation industry and from flight attendants' perspectives.
Finally, ORC mediated the relationship between HRD and TOI. This finding follows the prevailing SET theory (Blau, 1964), which carries the fundamental assumption that organizational practices can install a sense of obligation and reciprocity, further influencing employees' attitudes and behaviors. This study demonstrates that employees were committed because Royal Jordanian Airlines has a fair HRD system. This high level of commitment resulted in lower levels of TOI because its employees appear to be highly HRD, ORG and turnover intention attached to their organization. Nawaz and Pangil (2016) delineated the vital role of ORC as a mediator between HRD and TOI. Evidence from past research supports this study's results, which claimed that HRD, via ORC, negatively affected TOI (e.g. Juhdi et al., 2013;Kadiresan et al., 2015).

Managerial implications
The aviation industry is constantly plagued with high staff turnover, resulting in the high labor costs of recruiting and training new replacements. The present study has several responsive implications for managers in the industry. Employee ORC is vital for most organizations (given its usefulness in the sustainability of work activities and outcomes), resulting in increased productivity. Its findings show how HRD functions as a resource and medium that aviation industry managers can capitalize on to nurture ORC. The vital managerial implications of this study concern the role of HRD on critical employees and work outcomes. Organizations that invest in HRD activities tend to nourish their workforce commitment through increased attachment and identification, a sense of obligation and growth opportunities. As considerable resource investment is required to retain employees, the findings suggest that investment in HRD could function as a buffer for TOI. Supportive HRD practices contribute to employees' desires to remain. Employees are less likely to leave if they believe that their employer is supportive and fair, and is objective on compensation and performance appraisals. Multilateral efforts may be beneficial to reduce TOI. So, managers should invest in HRD to foster ORC among their workforce to reduce undesirable work outcomes, such as TOI.

Limitations, future studies and implications
This study has some limitations. First, only three HRD factors were examined in this research. Given that HRD has various forms of conceptualization with diverse factors, future research work may incorporate and investigate other factors, such as promotion and career planning (Uddin et al., 2016). Second, the collected data originated from flight attendants in the aviation industry and a single country (Jordan), limiting the researcher's ability to generalize the results to other industries and countries. Additional research is required in other sectors in Jordan and worldwide. Third, besides ORC, other attitudinal variables that can function as valuable mediators in the relationship between HRD and TOI should be investigated. For instance, upcoming studies could involve mediating variables, such as career growth and organizational engagement, which might explain the hypothesized relationships better.

Conclusion
In the current study of an aviation company in Jordan, the influence of HRD on TOI through the indirect effects of ORC was scrutinized. HRD negatively impacted TOI and positively affected ORC, which, in turn, impacts TOI negatively. The findings delineate the indirect effect of HRD on TOI through ORC. This research's findings are consistent with theory and past findings. The results suggest that flight attendants from Royal Jordanian Airlines are likely to show lesser commitment and substantial TOI when they feel their HRD practices are poor. These results may guide airline managers and policymakers to develop retention strategies to minimize TOI.