Introduction

All organizations, including higher education organizations, are trying to compete in today's challenging and changing world to meet their goals of recruiting staff to work beyond their job requirements. Daily increase of contribution of employees to value creation in a dynamic competitive business system has led to a change in the look of managers to employees from a single source of production to an organizational citizen (^{Jafari & Majidi-Moghadam, 2013}). Organizational citizenship behavior (OCB) includes employee voluntary behaviors that are not part of their formal duties and are not directly considered by the formal organizational reward system, although they increase the overall effectiveness of the organization (Organ, 1988).

This term was first used by ^{Organ in 1988}, who included five aspects as part of such phenomenon: (i) altruism (voluntary contributions to others, sacrifice, peace, hope and morale, and prevention of work-related events); (ii) conscientiousness (behaviors that guide a person in performing their duties above the expected level, such as punctuality in performing tasks); (iii) sportsmanship (tolerating complications and inevitable problems of work without objection); (iv) civic virtue (responsible partnership and commitment to the life of the organization); and (v) courtesy (polite behaviors that prevent workplace problems, such as helping others to prevent problems or action to reduce others' problems) (^{Podsakoff, Mackenzie, Paine, & Bachrach, 2000}).

Organizations are not able to develop their effectiveness without the willingness of volunteers to collaborate. Employees with an OCB act beyond their duty and express their efforts, energy, and insight to flourish their abilities for the benefit of the organization. In this case, employees usually pass on their personal interests and prioritize their responsibilities in the interests of others. Accordingly, OCB has positive outcomes, such as increased productivity, better performance, greater effectiveness (^{Ahangari, Hajinejad, & Khanmohammadi, 2017}; ^{Kilinc & Ulusoy, 2014}), positive relationships between employees, greater efficiency in resource allocation, and reduced maintenance costs, thus providing the flexibility needed to innovate and improve customer service (^{Sanaatjoo & Mahmoudi, 2015}). Besides, good corporate citizens enable the organization to efficiently utilize scarce resources and improve and enhance the ability of colleagues and managers to do their jobs. Organizations that promote citizenship behavior are attractive places to work and will be able to recruit and retain the best people, as well as gain organizational trust and customer satisfaction (^{Bahari-far, Javaherikamel, & Ahmadi, 2011}).

Higher educational institutions are organizations where OCB is a necessity if the institutions are to survive (^{Eyupoglu, 2016}). In addition, OCB helps organizations to be successful in the unpredictable contemporary environment and accelerates novelty and creative approaches. Higher educational organizations are encouraged to make every feasible endeavor to develop, maintain and preserve a favorable work climate that fosters citizenship behavior among the employees. It is necessary for higher educational institutions to adopt and encourage OCBS so as to generate a better working environment and to enhance work performance (^{Waheed & Ahmad-Shah, 2017}). When staff display organizational citizenship behavior, their level of commitment will improve, and the performance of higher education institutions will improve as well. Therefore, these institutions will be able to meet their targeted goals and serve the community better (^{Saheed-Adewale, Ghavifekr, & Megat, 2018}).

Given the positive implications of OCBS, recognizing the predictors of these behaviors is of great importance to organizations. In this regard, a number of variables have been studied in the studies as predictors of OCB. According to the results of these studies, variables such as leadership styles (^{Lian & Tui, 2012}), organizational trust (^{Zhang, Zhao, & Fang, 2010}), job satisfaction (^{Swaminathan & Jawahar, 2013}), organizational commitment (^{Ibrahim & Aslinda, 2013}), and organizational justice (^{Di-Fabio & Palazzeschi, 2012}) can provide a basis for the development and strengthening of OCB. Among these, one of the challenging variables is leadership style, which is defined as techniques used to influence and direct the activities of others (^{Rezaei, Yarmo-hammadian, & Mahmoodzadeh-Ardakani, 2017}).

In the past, organizations were working in steady environments, so they needed less change; however, they are now competing in dynamic environments (^{Moradi, Jafari, Omidi, & Alidost, Ghahfarokhi, 2014}). In the newest division of leadership styles, leaders use two sets of different behaviors, including transformational and transactional leadership, to influence their followers (^{Nasiri-Valikbani & Emadi-Pashakalai , 2016}).

Transformational leadership is a complex and dynamic process that tries to create an emotional relationship with its followers, in which the leaders affect their values, beliefs, and goals. Leaders penetrate on beliefs, values, and goals, and have an extraordinary effect on their followers (^{Saki, Dasti, & Nasri, 2015}). Transformational leadership, with an emphasis on the development of followers, encourage them to self-fulfillment and endeavor to fulfill their obligations beyond expectations (^{Asgari, Silong, Ahmad, & Abu-Sama, 2008}). These leaders have a clear vision of the future, focusing on changing their employees' attitudes and assumptions toward mission and organizational goals and encourage their employees with values such as friendship, honesty and responsibility to look at the interests of the organization beyond their own interests (^{Arefi, Rashid, & Abochenari, 2012}). The leader that transforms employees is constantly trying to inject this thought into their followers, so that they possess superior powers and abilities and not only have to deal with current issues but also look at things from a new perspective. In addition, transformational leadership encourages organizational learning and provides policy for critical periods (^{Shadraconis, 2013}), and it is effective in promoting and improving organizational effectiveness (^{Ling & Ling, 2012}) . With increasing levels of skills, capabilities, commitment of employees through transformational leadership, and increased job satisfaction (^{Nasiri-Valikbani & Emadi-Pashakalai, 2016}), employees are more likely to work than their usual duties and function beyond the organization's expectations (^{Bahadori & Nayeri, 2017}).

Transactional leadership is also a kind of leadership that follows the leader-member exchange theory. Therefore, as a social exchange process, leaders under this approach rely on rewards and organizational punishments to increase the performance of their employees (^{Zhang, Tsui, & Wang, 2013}) . In this process, leaders have in their dealings with their followers a contractual relationship or trademark, so that employees receive tangible rewards for higher performance and improved performance of tasks. On the contrary, if they do not observe the rules and regulations or if they fail to meet the standards in accordance with the standards, they will be punished (^{Gholamzadeh, Haghshenase, & Mohammadkhani, 2015}). Based on this, transactional leadership promotes followers by focusing their attention on their personal and interactive interests (Zhang et al., 2013). However, the main limitation of transactional leadership is that among employees it does not result in long-term commitment to organization.

While transformational leadership leads followers to act in accordance with their expectations, it also prompts them to go beyond what is expected (^{Nasiri-Valikbani & Emadi-Pashakalai, 2016}). In their study, ^{Asgari et al. (2008)} showed that transformational leadership has more predictive power in developing organizational citizenship behavior compared to transactional leadership. Additionally, ^{Moradi, Hamidi, Sajjadi, Jafari, and Moradi (2011)} identified a positive and significant relationship between transformational and transactional leadership and ocb, with transformational leadership being a stronger predictor of OCB. In contrast, Ngunia, Sleegers and Denessen (2008) showed that transformational leadership does not have a significant relationship.

In regard to the differences between transformational and transactional leadership and the contradictory results of the studies above, this work seeks to determine whether transformational leadership will be more likely to lead to OCB than a transactional leadership style. In any case, transformational and transactional leadership play a different role as one of the leading methods for predicting OCB and developing an OCB model. Although the question of whether this effect is direct or indirect remains on the stage. Given the consequences of transformational and transactional leadership, employees seems to be affected by perceived organizational support and job satisfaction, possibly affecting the OCB studied in the model.

Based on ^{Burns' theory of transformational leadership (1978)}, transformational leaders show active behaviors that include providing a shared responsibility, seeking change, working with employees, focusing on the inner needs of high-level employees, and helping to create higher job satisfaction, higher motivation and higher employee sense. Conversely, exchange leaders are passive and only seek to maintain the status quo, with attention focused on the lowest level of employees' needs, their look at work, finding errors and deviations in work and exercising punishment in order to increase positive attitude and achieve higher levels of success. This type of leader uses extrinsic motivators and tangible rewards for encouraging their collaborators and use contingency punishment to make them follow orders (^{Eskandari, 2015}). These differences in two leadership styles can lead to different outcomes, including job satisfaction and organizational support for employees (^{Salimi, 2015}). On the other hand, the results of various studies indicate that perceived organizational support (^{Kaffashpor, Shojaean, & Alaghebandi, 2017}; ^{Wang & Wong, 2011}) and job satisfaction (^{Mehboob & Bhutto, 2012}; ^{Rezaei & Mahmoudi, 2017}) can predict OCB.

Perceived organizational support is the general feeling and belief of individuals in this regard that the organization values cooperation, the support of its members, and is concerned about their prosperity and future (^{Lamastro, 1999}), which creates a sense of duty toward giving importance to the organization (^{Luxmi & Yadav, 2011}). The perception of an organization's support by employees increases the expectation that their efforts are in line with the goals of the organization and that they will be rewarded. When this is anticipated, the interchange cycle will continue to grow. In other words, when organizations deal with their employees with a good deal of interest and focus on them, they convey the message that the organization values them, so that the employees will be more profitable (^{Shahi, Andarz, Andarz, & Yasini, 2017}), show higher levels of job commitment (^{Mehdibeigi, 2017}), and have higher job satisfaction levels and more favorable attitudes toward the organization (^{Kaffashpor et al., 2017}). On this regard, Lamastro (1999) showed that perceived organizational support increases productivity and assists colleagues, organizational progress, organizational commitment, and organizational citizenship behaviors. ^{Rezaei and Mahmoudi (2017)} stated that when individuals have a fair understanding of the behavior of managers and supervisors and believe that managers consider them in their decisions, they are more satisfied toward their job, which, consequently, leads to an increase in cessation behaviors and organizational citizenship behaviors.

Job Satisfaction is a set of emotions, feelings or attitudes related to the work environment of an individual and is described as a pleasant feeling of personal perceptions related to the pursuit of a job and the values of a person (^{Alonderiene & Majauskaite, 2016}). This is one of the organizational variables that can affect the physical, psychological and spiritual health of individuals, improve their quality of life, and ultimately improve the efficiency of any organization (^{Esmaeili & Seidzadeh, 2017}; ^{Simone, Cicotto, Lampis, 2016}). Empirical findings indicate that high job satisfaction is a major determinant of important organizational implications, such as labor market dynamics, employee retention (^{Pacheco & Webber, 2016}), organizational performance improvement (^{Bacotic, 2016}), and productivity (^{Charoensukmongkol, Moqbel, & Gutiérrez-Wirsching, 2016}).

On the other hand, low job satisfaction, because of poor performance, low productivity, and high employee quitting, represents high costs for an organization (^{Rhodes & Toogood, 2016}). ^{Zare-Khafri and Hasani (2014)} stated that job satisfaction creates a positive affective status in the organization, which is related to social and participatory behaviors. By the way, those who have more job satisfaction in the organization are introducing behaviors that could be in the form of organizational citizenship behaviors, since their interaction with the organization has provided them with job satisfaction.

Considering the above, it can be said that focusing on OCB and its strengthening can lead to improve many individual and organizational performance indicators. Therefore, the recognition of factors related to OCB is useful for managers seeking to increase job satisfaction and organizational support. Consequently, this study addresses the role of transformational and transactional leadership in OCB, with perceived organizational support and job satisfaction being the mediating roles in this relationship. Figure 1 presents the conceptual model proposed for this research.

Source: authors.

Figure 1 Organizational citizenship behavior model in relation to transformational and transactional leadership. 

Methodology

Data was gathered in 2018. The sample included white-collar employees at the University of Birjand, Iran, a governmental institution established in 1975 known for being the oldest university in eastern Iran. A pilot test of 30 employees was conducted to assure the reliability of the scales. Simple random sampling was used to select the sample size. Data collection was carried out in April, 2018. Upon the reception of permission from the human resources managers, the researchers invited the employees to complete the questionnaires. From a total of 250 questionnaires distributed, 201 were returned, excluding 49 useable responses. The response rate was 80.4%. This study used standard survey instruments made of five components (demographic, transformational leadership, OCB, perceived organizational support, and job satisfaction) to extract information. All the instruments chosen are widely utilized and their reliability has been established.

In order to measure employees' OCB, we used the five-dimension (altruism, courtesy, sportsmanship, civic virtue, and conscientiousness) scale developed by ^{Podsakoff and MacKenzie (1989)}, which consists of 24 items (e.g. "In this organization, an employee helps others who have heavy workloads"). The items of this construct were measured on a five-point Likert scale, ranging from (1) "strongly disagree" to (5) "strongly agree." The psychometric properties of the scale have been reported in previous studies. The Cronbach's a reliability of the instrument in this study was 0.87.

The Multifactor Leadership Questionnaire (MLQ) -also known as MLQ 5X, short instrument or the standard MLQ-measures a broad range of leadership types, from passive leaders to leaders who give contingent rewards to followers and to leaders who transform their followers into becoming leaders themselves. MLQ evaluates three different leadership styles: transformational, transactional, and passive-avoidant. This instrument is recognized as a well-established instrument for measuring transformational leadership and has been extensively researched and validated. Avolio and Bass's MLQ manual shows strong evidence for validity. The items of this construct were measured on a five-point Likert scale, ranging from (1) "strongly disagree" to (5) "strongly agree." The Cronbach's α reliability of the instrument for transformational and transactional leadership in this study were 0.94 and 0.81, respectively.

The survey of Perceived Organizational Support (pos) is a one-dimensional measure of the general belief held by an employee that the organization is committed to him or her, values their continued membership, and is generally concerned about their well-being. pos questionnaire (8 items) was used by the modified scale of ^{Eisenberger (Eisenberger, Cummings, Armeli, & Lynch 1997}) to analyse the moderating effect on autonomy and affective commitment. Seven-point Likert scale was used to get respond from respondents like (1 = strongly disagree, 7 = strongly agree). The Cronbach's α reliability of the instrument in this study was 0.82.

The Employee Satisfaction Inventory (ESI) was developed by Koustelios in 1991. It included 24 questions that measure six dimensions of job satisfaction: (i) working conditions (5 questions); (ii) earnings (4 questions), (iii) promotions (3 questions); (iv) nature of work (4 questions); (v) immediate superior (4 questions); and (vi) the institution as a whole (4 questions). The responses were given in a five-point Likert scale (1 = strongly disagree; 5 = strongly agree). The Cronbach's α reliability of the instrument in this study was 0.75.

Results

The data obtained from 201 employees were analysed through spss 24 and AMOS 22. In this study, 99 of the participants were males and 98 females with an experience range of less than 10 years (55), 11-20 years (71), and more than 21 years and over (61). Their ages were in the ranges of less than 30 years (23), 31-40 years (69), and more than 41 years and over (97). In addition, 165 of the participants were married and 24 were single. The standardized Cronbach Alpha for each variable is provided in table 2. All the scales had coefficient Cronbach Alpha over 0.75.

Table 1 Descriptive variables 

Note: The questions were not mandatory. This is the reason why the number of respondents does not coincide.

Source: authors.

A correlation analysis was conducted on all variables in order to explore the relationship between variables. The bivariate correlation procedure was subject to a two tailed of statistical significance at two different levels (p < 0.01) and (p < 0.05). Descriptive statistics and correlations for all study variables are reported in table 2, which examines the correlations among transformational leadership, transactional leadership, perceived organizational support, job satisfaction, and organizational citizenship behavior. According to this table, transformational leadership was positively associated with perceived organizational support (r = 0.48, p < 0.01), job satisfaction (r = 0.48, p < 0.01), and OCB (r = 0.50, p < 0.01). Furthermore, transactional leadership yielded significant (p < 0.01) correlations of -0.31 with perceived organizational support, -0.25 with job satisfaction, and -0.38 with OCB. Likewise, perceived organizational support yielded significant (p < 0.01) correlations of 0.37 with job satisfaction and 0.44 with OCB. In addition, job satisfaction was significantly correlated with OCB (r = 0.64, p < 0.01).

Hypothesis H1 predicts that pos will mediate the relationship between transformational leadership and OCB. The result in table 2 shows positive and significant relationships between transformational leadership and OCB (r = 0.50, p < 0.01). The effect of transformational leadership on OCB in an indirect path was confirmed by the path analysis result in the table 3 (β = 0.23, p < 0.01). Transformational leadership style is positively related to the pos (r = 0.48, p < .01; β = 0.32, p < 0.01). Also, there is a significant and positive relationship between the pos and OCB (r = 0.44, p <0.01; β = 0.14, p < 0.01). This all positive and significant paths in the triangular relationship between transformational leadership, pos and OCB give rise to the speculation that the intermediate variable (i.e. POS) could be a mediating variable. Further analysis was conducted to assess the significance of an indirect effect of transformational leadership on OCB through pos. The result of this analysis (table 3) shows that pos contributed significantly to the relationships between transformational leadership and OCB (t = 2.96). This mediation effect was significant at 0.01 level.

Table 3 Results of single mediation models 

a, TFL → mediator path; b, mediator → OCB path; c', TFL → OCB path when the mediator is included in the model (i.e., direct effect); R², amount of variance explained in OCB; AR², change in explained variance when the mediator is added to the model compared to the total effect of TFL on OCB.

*p < 0.05,

**p < 0.01.

Hypothesis H2 predicts that job satisfaction will mediate the relationship between transformational leadership and OCB. The result in table 2 shows a positive and significant relationship between transformational leadership and OCB (r = 0.50, p < 0.01). The effect of transformational leadership on OCB in an indirect path was confirmed by path analysis results in table 3 (β = 0.23, p < 0.01). Transformational leadership style is positively related to job satisfaction (r = 0.48, p < 0.01; β= 0.47, p < 0.01). Besides, there is a significant and positive relationship between job satisfaction and OCB (r = 0.64, p < 0.01; β = 0.45, p < 0.01). This positive and significant paths in the triangular relationship between transformational leadership, job satisfaction and OCB show there is an intermediate variable, that is, job satisfaction could be a mediating variable. Further analysis was conducted to assess the significance of an indirect effect of transformational leadership on OCB through job satisfaction. Result shows that job satisfaction contributed significantly to the relationships between transformational leadership and OCB (t = 5.76). This mediation effect was significant at 0.01 level.

Hypothesis H3 predicts that pos will mediate the relationship between transactional leadership and OCB. The result in table 2 shows a negative and significant relationship between transactional leadership and OCB (r = -0.38, p < 0.01). The effect of transactional leadership on OCB in an indirect path was further confirmed by path analysis result in figure 2 (β = -0.20, p < 0.01). In addition, the transactional leadership style is negatively related to pos (r = -0.31, p < 0.01; β = -0.18, p < 0.01). Also, there is a significant and positive relationship between the pos and OCB (r = 0.44, p < 0.01; β = 0.14, p < 0.01). This all significant paths in the triangular relationship between transactional leadership, pos and OCB shows there is an intermediate variable, that is, pos could be a mediating variable. Further analysis was conducted to assess the significance of an indirect effect of transactional leadership on OCB through pos. Result shows that the pos contributed significantly to the decreased relationships between transactional leadership and OCB (t = -2.59). This mediation effect was significant at 0.01 level.

Hypothesis H4 predicts that job satisfaction will mediate the relationship between transactional leadership and OCB. The result in table 2 shows a negative and significant relationship between transactional leadership and OCB (r = -0.38, p < 0.01). The effect of transactional leadership on OCB in an indirect path was further confirmed by path analysis result in figure 2 (β = -0.20, p < 0.01). Results also show that transactional leadership style is related negatively to the job satisfaction (r = -0.25, p < 0.01; β = -0.20, p < 0.01) and a significant and positive relationship between job satisfaction and OCB (r = 0.48, p < 0.01; β = 0.45, p < 0.01). This all significant paths in the triangular relationship between transactional leadership, job satisfaction and OCB, show that the intermediate variable job satisfaction could be a mediating variable. Further analysis was conducted to assess the significance of an indirect effect of transactional leadership on OCB through job satisfaction.

Source: authors.

Figure 2 Hypothesized model. 

The result of this analysis (table 3) shows that job satisfaction contributed significantly to the decreased association between transactional leadership and OCB (t = -3.47). This mediation effect was significant at 0.01 level.

The fitness indices shown in table 4 indicate that X²/df, RMSEA, CFI, NFI, CFI, IFI and TLI. The Comparative Fit Index [CFI] (^{Bentler, 1990}), Goodness of Fit Index [CFI] (^{Hair, Anderson, Tatham, & Black, 1998}), Normed Fit Index [NFI], and Root Mean Square Error of Approximation [rmsea] (^{Steiger, 1990}) were used in judging fit. CFI is a recommended index of overall fit (^{Gerbing & Anderson, 1992}); CFI measures the fitness of a model compare to another model (Hair et al., 1998); NFI measures the proportion by which a model improves fit compared to null model (Hair et al., 1998); and RMSEA provides information in terms of discrepancy per degree of freedom for a model (Steiger, 1990). CFI, NFI, and CFI close to 1 indicate a very good fit of the model (Hair et al, 1998). On this regard, ^{Browne and Cudeck (1992)} suggest that an RMSEA of 0.05 indicates a close fitting model, while values up to 0.08 represent reasonable errors of approximation for model indices with acceptable fitness values. Table 4 presents the results of measurement models used to test the hypothesis with regard to model paths. The fit indices (CFI, NFI and CFI) were adequate. The last model had the highest fit indices (CFI = 0.993; NFI = 0.985; CFI = 0.993; TLI = .967; IFI = .994) and also the lowest RSMEA (0.063). These values explained that this model is the best fit to test the hypothesis. Therefore, the model appears to be acceptable.

Final Considerations

The goal of this study was to examine the links between transformational leadership, transactional leadership, perceived organizational support, job satisfaction, and organizational citizenship behavior. All developed hypotheses were supported by the data obtained. Findings of this study showed the expected significant link between transformational leadership, transactional leadership and employees' OCB. These outcomes are consistent with prior empirical research (e.g. ^{Jha, 2014}; ^{Khalili, 2017}; ^{Lee, Woo, & Kim, 2018}; ^{Mekpor & Dartey-Baah, 2017}; ^{Suliman & Al-Obaidli, 2013}). For example, in a study of 50 organizations in Iran, with a sample of 2,021 employees, Khalili (2017) studied the influence of transformational leadership on OCB. Her findings validated that this type of leadership has a strong and positive impact on OCB. This result is consistent with Jha's work (2014) on the impact of transformational leadership behaviors on the OCB of 319 employees of different five-star hotels, which revealed a significant and positive effect of transformational leadership on OCB.

These findings tell us that when organizational leaders demonstrate transformational leadership, their employees are more involved in OCBS and, therefore, capable of going beyond their defined obligations and responsibilities, assist others in their tasks and assignments, and attend to their fellow workers' both individual and professional needs in the workplace (^{Babcock-Roberson & Strickland, 2010}). This result was also consistent with ^{Mekpor and Dartey-Baah (2017)}, who examined the impact of transformational and transactional leadership behaviors on OCB employees in the Ghanaian banking sector. Their findings revealed that although transformational and transactional leadership styles predicted employees' OCB, transformational leadership is more significant. Thus, transformational leaders are more capable of leading their subordinates to take actions beyond their prescribed roles.

The findings of this study showed the expected significant link between transformational leadership, transactional leadership and perceived organizational support. These outcomes are consistent with prior empirical research (e.g. ^{Kurtessis et al, 2017}; ^{Suifan, Abdallah, & Al-Janini, 2018}). For example, in a study of 369 employees working in Jordanian banks, Suifan et al. (2018) studied the influence of transformational leadership on perceived organizational support. Their results indicate that transformational leadership positively affects perceived organizational support and validated that transformational leadership has a strong and positive impact on pos. This result was consistent with ^{Stinglhamber, Marique, Caesens, Hanin, and De-Zanet (2015)}, who examined the impact of transformational leadership on followers perceived organizational support in a sample of 287 employees of a water producer organization. The results of this study show that when employees strongly identify their supervisor with the organization, a transformational leadership style is positively related to pos. Moreover, in a meta-analytic assessment of organizational support theory (OST) using results from 558 studies, Kurtessis et al. (2017) found that pos was more strongly related to transformational leadership (p = 0.56) than transactional leadership (p = 0.21). Consistent with organizational support theory, transformational leaders, who display a concern for the needs of their subordinates and inspire subordinates to dedicate themselves to organizational goals, more strongly convey pos than transactional leaders.

The findings of our research study showed the expected significant link between transformational leadership, transactional leadership and employees' job satisfaction. These outcomes are consistent with prior empirical research (e.g. ^{Ghorbanian, Bahadori, & Nejati, 2012}; ^{Hu, Yang, & Islam, 2010}; ^{Loganathan, 2013}; ^{Negussie & Demissie, 2013}). In a study of 123 salespeople in the consumer product industry in Taiwan, Hu et al. (2010) investigated the influence of transformational leadership on job satisfaction, identifying a positive and statistically significant relationship between sales managers' transformational leadership and sales associates' job satisfaction. Besides, the results of Loganathan's (2013) work showed statistically significant relationships between overall transactional leadership and job satisfaction, overall transformational leadership, and job satisfaction.

These findings suggest that managers in organizations in Iran may be able to engage their employees in citizenship behaviors by paying attention to their own transformational leadership, rather than transactional leadership behaviors. The results of our study support the positive and significant influence of transformational leadership behaviors on employees' OCB, pos and job satisfaction. Additionally, our results support the negative and significant influence of transactional leadership behaviors on employees' OCB, pos and job satisfaction, as well as the mediating role of pos and job satisfaction on the transformational and transactional leadership (employees' OCB association).

Although research on the association between transformational and transactional leadership and OCB has gained attention, empirical studies regarding the mediating role of pos and job satisfaction on the link between transformational and transactional leadership and employees' OCB remain scarce. With regard to the effect of employees' satisfaction and pos on their own OCB, as well as on the transformational and transactional employees' OCB relationship, our findings pointed out that employees with highest level of satisfaction have a robust willingness to be committed in citizenship behaviors. As a conclusion, transformational leaders have a more positive impact on employees' OCBS in organizations in Iran.

This study examined the relationships between transformational and transactional leadership, job satisfaction, pos and OCB in the University of Birjand. While most prior studies have examined transformational leadership-OCB and transactional leadership-OCB relationships in developed countries from the western world, testing the moderating influence of employees' pos and job satisfaction between transformational leadership and employees' citizenship behaviors in universities remains scarce.

The importance of this study is threefold. First, it examines the relationship between transformational leadership and employees' OCB in a developing country such as Iran. Second, it studied the relationship between employees' job satisfaction, pos and their own OCB in Iran. Third, our research explores the role of employees' job satisfaction, pos as a mediator on the transformational leadership and employees' OCB association in an Iranian university. Therefore, this study is assumed to be utilized to comprehend the crucial roles of transformational leadership, job satisfaction and pos in showing more extra-role behaviors, like OCB, from employees in higher education institutions in Iranian.

The present study showed that transformational leadership behaviors, along with the job satisfaction of employees, were key factors for the management of human resources in an Iranian university. This study also emphasized that transformational leadership behaviors and employees' job satisfaction and pos are important and should be used and managed in order to ensure improved organizational outcomes, especially in the university context. If universities can apply transformational leadership styles and enhance employees' job satisfaction, both employees' behaviors and their outcomes will be improved. To this end, managers in universities in Iran should identify measures to improve not only their own leadership style but also job satisfaction levels of their employees.

Considering that managers with high levels of transformational leadership have greater impact on their employees, and employees with high levels of job satisfaction report better relationships with coworkers, these two conditions can contribute to meet organizational goals. Thus, it is absolutely necessary to implement transformational leadership by managers and improve job satisfaction by employees to foster OCB in Iranian higher education institutions. Based on these findings, managers with a transformational leadership style are more likely to expertly manage their employees and employees with high satisfaction levels are more likely to favorably engage with coworkers. Therefore, universities should select managers with a transformational leadership style to involve employees in the fulfillment of their objectives. Finally, particular training programs should be developed to promote better transformational leadership behaviors in universities.