THE EFFECT OF SERVANT LEADERSHIP ON ORGANIZATIONAL CITIZENSHIP BEHAVIOR : THE ROLE OF TRUST IN LEADER AS A MEDIATION AND PERCEIVED ORGANIZATIONAL SUPPORT AS A MODERATION

JEL Code: D13 Current organizational behavior studies emphasize the importance of the human aspect. Therefore, leadership as a study of organizational behavior needs to focus on human aspects. The servant leadership (SL) popularized by Greenleaf in 1970 was in line with the idea. SL is explicitly defined as leadership that focuses on serving the needs of subordinates (human aspects). SL is believed to affect subordinate positive behavior which is indicated by organizational citizenship behavior (OCB). However, in the effect of SL on OCB, there is still debate over whether both of them have a direct or indirect impact. The role of organizational context is also not considered in previous studies. This study aims to examine the role of trust in leaders (TIL) as a mediating variable and perceived organizational support (POS) as a moderating variable on the effect of SL on OCB. A total of 238 respondents were collected in the current study in various regions of Indonesia. The results showed that SL had a significant positive effect on OCB. POS was also reported to significantly moderate the effect of SL on OCB. In addition, it was unexpectedly reported that TIL did not mediate the effect of SL on OCB. POS also reported not moderating the effect of SL on OCB through TIL. The arguments in explaining these results are discussed in more detail in the discussion section of this article. ___________ * Corresponding Author at Department of Economics, Faculty of Economics and Business, Universitas Gadjah Mada, Jalan Socio Humaniora No. 1, Yogyakarta 55182, Indonesia. E-mail address: astrini.diah@gmail.com (author#1), JOURNAL OF LEADERSHIP IN ORGANIZATIONS


Introduction
Current organizational studies emphasize the importance of human aspects in organizations.It is essential to change the management paradigm from the one who sees humans only as a means of production in the direction that sees humans as the primary resource in the production of output.The shift in focus in the study of organizational behavior also has an impact on the need to change the paradigm in leadership studies (Van Dierendonck, 2011).This is because leadership is one topic that is quite popular in organizational behavior research.In line with the leadership approach that emphasizes on the human aspect, the concept of servant leadership is believed to be following the current needs of the organization (Choudhary et al., 2013;Van Dierendonck, 2011).Servant leadership (SL) is one of the leadership styles that focuses on human aspects (people-centered) and has become a concern of current researchers (Choudhary et al., 2013;Barbuto & Wheeler, 2006;Liden, 2012;Pekerti & Sendjaya, 2010 ).SL explicitly places individual needs as a top priority over organizational goals (Smith et al., 2004;Stone et al., 2004;Barbuto & Wheeler, 2006;Graham, 1991;Stone et al., 2004), so that relationships are believed intertwining between leaders and subordinates is more long-term.
SL is positioned as a new study in leadership studies (Van Dierendonck, 2011).Therefore, it is reasonable if there is still little attention to SL studies compared to other leadership styles (i.e.transformational leadership) in the leadership literature (Stone et al., 2004;Barbuto & Wheeler, 2006: Hoch et al., 2018).The topic of SL is considered to still require much support for empirical research (Stone et al., 2004).Based on this, empirical research on this SL topic still provides a great opportunity.In addition, since SL was first introduced, Greenleaf (1977) did not inherit the characteristics of SL that were of a standard nature (Van Dierendonck, 2011).As a result, researchers build their characteristics in defining SL (see Van Dierendonck, 2011p.1241).With consideration of many researchers who developed the characteristics of each SL, it is relevant for further research to use instruments that have been compiled and meet the key characteristics of SL.Van Dierendonck (2011) describes that of the seven dimensions of measurement reviewed by researchers in the field of SL, only the measurement dimension was developed by Laub (1999) and Van Dierendonck & Nuijten (2010) which met the six key characteristics of SL.Therefore, it is essential for further research to use measurement dimensions that have met the key characteristics of SL where previous research was not concerned about this.
Furthermore, Podsakoff et al. (1990;2000) suggested the importance of revealing leadership effectiveness.One way to measure the effectiveness of organizational leadership is by testing the effect of leadership on employee behavior (Neubert et al., 2008;Wang et al., 2005).Some studies report that leadership that focuses on empowering subordinates can motivate subordinates to play outside of the direction of organizational routines (Podsakoff et al., 1990;2000).Therefore, SL as a leadership style that focuses on the development and needs of subordinates (peoplecentered) is believed to be encouraging subordinates to behave extra or what is termed organizational citizenship behavior (OCB).The opinions above are in line with the social learning theory (Bandura, 1971) and social exchange (Blau, 1964).
However, in the effect of SL on OCB, there were still inconsistencies in the findings of the researchers.Previous studies have confirmed that there is a positive effect of SL on OCB (Dixon, 2013;Mathur & Negi, 2014).On the other hand, the Harwiki (2013) study reported that SL had no effect on OCB.The inconsistency issue indicates the potential for moderating variables that can strengthen the effect of SL on OCB.The results of the study reported by Harwiki (2013) are suspected because there are roles from organizational contexts that are not considered.The results of the empirical study indicate that in addition to leader behavior, the organizational context is believed to play a role in the effect of SL on OCB.The logic is in accordance with contingency theory wherein the context of the current research, in addition to examining the effect of SL on OCB it is also necessary to consider contextual factors, including support from the workplace (organization).
In line with the concept of SL, the organization that is perceived as focusing on the welfare of subordinates is expected to strengthen the positive effect of SL on subordinate OCB further.Eisenberger et al. (1986) who introduced the concept of perceived organizational support (POS) defined it as an idea where employees build trust that organizations care about their welfare.The idea is believed to be in line with the objectives of service leadership where it focuses on the human aspect (subordinates/employees).Thus, the relevant POS is positioned as a contextual factor which is believed to be effective in strengthening the effect of SL on subordinate OCB.
In addition, empirical evidence also reports an indirect relationship in SL mechanisms towards OCB (Zehir et al., 2013;Wu et al., 2013;Hunter et al., 2013;Newman et al., 2015).This empirical support indicates that there are potential mediating variables in the effect of SL on OCB.A leader who applies SL will encourage the trust of subordinates towards their leaders (Page & Wong, 2000in Chan & Mak, 2014).The credibility of a credible SL leader will enhance his extra role behavior (i.e., OCB).This logic is in line with affective event theory (AET) (Weiss & Cropanzano, 1996) that certain stimuli will have an impact on attitudes and then produce behavior.The urgency of the presence of trust in leaders (TIL) is supported by previous studies which suggest further studies can consider TIL as a mediator in the SL mechanism in OCB (Dixon, 2013;Ehrhart, 2004;Zehir, 2013;Bambale, 2014).Bambale (2014) also revealed that the role of TIL mediation had not been a concern in uncovering the SL mechanism against OCB.In fact, trust has an important role in the leadership process (Podsakoff et al., 2000;Pillai, R. et al., 1999;Liu, J. et al., 2010;Joseph & Winston, 2005;Jung & Avolio, 2000).
Consistent with the issue of TIL as mediator and POS as moderation that was built before, then in the current study propose a moderated mediation model.The model is supported by studies from Burke et al. (2007) in the analysis of the method which reveals that the effect of leader behavior on subordinates through TIL does not occur in a vacuum.Furthermore, Burke revealed that one of these possibilities was organizational factors.In the context of current research, situational factors namely high POS will increase the trust of subordinates to leaders who focus on their subordinates.

Literature Review
The Effect of SL on OCB Greenleaf (1977) revealed that leaders who implement SL would inspire their subordinates to be someone who wants to serve others.Leaders who truly serve others will act as role models for their subordinates (Smith et al., 1983;Wu et al., 2013).This logic is in line with the social learning theory (Bandura, 1971) and social exchange theory (Blau, 1964).Social learning theory holds that a person tends to behave according to his social environment.If translated in the context of SL, leaders who are identified as focusing on serving the needs of their subordinates, such as empowering subordinates and serving their community (Hunter et al., 2013) will be role models for their subordinates.Thus, a subordinate who perceives his boss as a role model tends to behave similarly.Hunter et al. (2013) argue that a subordinate who imitates SL behavior will be shown by the behavior of helping others including colleagues and members in the community.
Besides, the effect of leaders on the behavior of subordinates is also based on social interaction.Referring to social exchange theory (Blau, 1964) that a subordinate who gets positive benefits from serving leadership will be compelled to reciprocate the benefits he receives.SL that gives a positive effect will be responded to by subordinates in a positive form such as increased performance and other prosocial behavior.The greatest effect of a leader who serves is when his subordinates can also transmit the purpose of his leadership, namely to serve others (Greenleaf, 1977).This argument has also been supported by empirical studies that reveal SL effects on OCB (Güçel & Begeç, 2012;Dixon, 2013;Mathur & Negi, 2014).Dixon (2013) conducted his research in the context of schools in Alabama, US.One of the results of his research reported that perceptions of leaders who served (focusing on subordinates) would encourage subordinate OCBs.Mathur and Negi (2014) who researched in India also revealed similar things.He explained that subordinates who benefit from a serving leader tend to help and care for others.Based on the theory and empirical studies, the first hypothesis is formulated as follows: Hypothesis 1: SL has a positive effect on OCB

The Effect of SL on OCB with POS as Moderating
Relying solely on the leader's role does not necessarily become the best way to influence the behavior of subordinates.In addition to stimulus from the leader, contextual factors also cannot be ignored.The argument is supported by contingency theory which holds that there is no one best way to achieve leadership effectiveness.Fiedler (1964) revealed that there are certain context factors that effect the leadership role of subordinate behavior (Fiedler, 1964).Based on this perspective, the effect of SL on OCB cannot be said to be the best one way.Therefore, the effectiveness of SL is considered to be proven when considering certain context factors that are considered to influence subordinate OCB.
The results of previous studies also reported inconsistencies in the effect of SL on OCB.Some researchers report a positive and significant effect between SL and OCB (Dixon, 2013;Mathur & Negi, 2014).On the other hand, the findings of Harwiki (2013) reported that the effect of SL was not significant on OCB.These findings indicate that there are moderating variables that can strengthen or weaken the effect of SL on OCB.
The results of previous studies also reported inconsistencies in the effect of SL on OCB.Some researchers report a positive and significant effect between SL and OCB (Dixon, 2013;Mathur & Negi, 2014).On the other hand, the findings of Harwiki (2013) reported that the effect of SL was not significant on OCB.These findings indicate that there are moderating variables that can strengthen or weaken the effect of SL on OCB.
The results of the Harwiki study (2013) revealed that SL effects were not significant for OCB in certain organizational contexts.Therefore, the organizational context that supports the positive effect of SL on subordinate OCB will be more believed to be effective when having similar goals/vision with the leader.That is, SL which focuses on serving the needs and welfare of subordinates will significantly effect subordinate behavior when in an organizational context that also supports the atmosphere of leadership serving.Eisenberger et al. (1986) define POS as employees' perception in building their trust that organizations care about their welfare.In line with these definitions, SL is believed to be in line with the POS concept, which has a common goal of focusing on the welfare of members/subordinates. Therefore, high POS is believed to be able to strengthen the positive effect of SL on subordinate OCB.
The high perceptions of subordinates towards the POS are characterized by high levels of trust in the organization.When subordinates perceive the organization is supporting their welfare, it further strengthens the positive effect of SL on subordinate OCB.Vice versa, low POS is characterized by organizations that are perceived to be less supportive and concerned about the welfare of subordinates.This is in line with the research of Erdogan and Enders (2007) who reported that POS has a role as moderating the effect of leaders on subordinate behavior.Based on these theories and empirical findings, the second hypothesis is formulated, namely: Hypothesis 2: POS moderates the effect of SL on OCB

The Effect of SL on OCB with TIL as Mediator
In contrast to the formulation of hypothesis 1 which supports direct effect, previous studies also reported an indirect effect between SL and OCB (Zehir et al., 2013;Newman et al., 2015;Hunter et al., 2013).The effect of SL on OCB is reported to be mediated by a number of variables including organizational justice (Zehir et al., 2013), LMX (Wu et al., 2013), and service climate (Hunter et al., 2013).In addition, Dulebohn et al. (2012) revealed that the view that the behavior of leaders directly effects OCB is an old leadership approach.
In line with that, the results of the meta-analysis conducted by Bambale (2014) suggested that further studies could consider the trust variable as a mediator in the effect of SL on OCB.This is because previous research has not focused on exploring the role of trust in the effect of SL on OCB.A number of other researchers in the SL field have also recommended the important role of trust in the effect of SL on OCB to be explored in subsequent studies (Ehrhart, 2004;Walumbwa et al., 2010;Dixon, 2013;Zehir et al., 2013).
This study focuses on the trust of subordinates to leaders (TIL) compared to other constructs of trust (i.e.organizational trust and trust in general).This is because TIL is a strong variable in explaining the relationship between leaders and subordinates (Tan & Tan, 2000;Dirks, 2000).Casimir et al. (2006) suggest that a leader who has credibility, competence, and focuses on the needs and welfare of his subordinates will encourage the attitude of trustees towards the leader.This argument is in line with Affective Event Theory (AET) which holds that positive stimulus will lead to a positive attitude, which means that positive stimulus from serving leaders will encourage subordinates' positive attitudes, namely trust in their leaders.The advanced flow of AET reveals that positive attitudes that arise will lead to positive behavior as well.Therefore, the attitude of trusting subordinates towards their leaders will encourage their sub-social pro-social behavior, namely extra-role behavior (OCB).When subordinates feel trust in leaders who serve, it will be easy for subordinates to behave in accordance with what is expected by the leader, including mutual assistance to fellow colleagues and the organization.
In addition to theoretical support, the results of empirical studies have revealed a positive effect between leadership that focuses on subordinates to trust in leaders (Dirks & Ferrin, 2002;Jung & Avolio, 2000).Specifically, Chan and Mak (2014) in their study reported the positive effect of SL on TIL.The positive effect of TIL on OCB has also been confirmed by a number of researchers (Deluga, 1995;Asgari et al., 2008).
In line with that, empirical studies have also confirmed the role of TIL as a mediator in the effect of SL on OCB.The results of the study from Trivers (2009) revealed that trust in leaders mediated SL against OCB.Williams (2012) also confirms the same thing, namely TIL mediates SL against OCB in the context of the United States (Misssi) Abid et al. (2015) also confirmed the same thing in the context of Pakistan.
Although the above argument explains TIL support as a mediator in the effect of SL on OCB, on the other hand, there are views from researchers who do not support it.Research from Reinke (2003;2004) for example indicates that TIL has a strong correlation with SL variables, so it is feared that both of them explain the same concept.Dennis and Bocarnea (2005) also revealed that trust is an element of SL characteristics.Based on the arguments and differences in empirical findings, the formulation of the current hypothesis aims to confirm the role of TIL as a mediator in the effect of SL on OCB.In addition, it aims to examine the role of TIL as a mediator as suggested by researchers (Ehrhart, 2004;Walumbwa et al., 2010;Van Dierendonck, 2011;Dixon, 2013;Zehir et al., 2013).Based on these theories and empirical findings, the third hypothesis is formulated, namely: Hypothesis 3: TIL mediates the positive effect of SL on OCB.

The effect of SL on OCB through TIL with POS as Moderating
Development of hypothesis 4 refers to two main issues.The first issue is consistent with the formulation of hypothesis 2 namely POS as moderating.The second issue is considering the role of trust in leaders (TIL) as a mediator in the effect of SL on OCB in accordance with the formulation of hypotheses 3.In the development of hypothesis 2, POS is a factor believed to be able to moderate the effect of SL on OCB.However, the development of hypothesis 4 now also considers the issue built on hypothesis 3, namely TIL as a mediator using the AET approach.
The logic built on AET is that the mechanism of SL towards OCB cannot be said to be effective if it does not consider the explanatory variables between the two.AET believes that positive stimulus will affect positive attitudes which then affect positive behavior.Therefore, SL as a positive stimulus from the leader will have an impact on a positive attitude that is indicated by a sense of trust in the leader.Trust in the leader ultimately affects positive behaviors including OCB (according to the development of hypothesis 3).
However, if you view the logic of contingency theory, the mechanism of SL towards OCB mediated by the TIL cannot be said to be effective if it has not considered the organizational context factor.Therefore, the developed POS is thought to be able to moderate the effect of SL on OCB through TIL.The high perception of subordinates for the support of the organization reflects the subordinates' perception that the organization cares about their welfare.The subordinates' perceptions will further strengthen the trust of subordinates towards serving leaders (SL) as representations of organizations which focus on the needs of subordinates.Thus, the attitude of trust from the subordinates will have an impact on their positive behavior in the form of extra roles (i.e OCB).
In line with that, Burke et al. (2007) in the meta analysis revealed that in the mechanism of effect leader behavior on subordinates through TIL does not occur in a vacuum.That is, there are a number of factors that can strengthen the degree of trust in leaders as mediators in the effect of SL on OCB, one of them being organizational factors.The results of these studies further strengthen that POS moderates the effect of SL on OCB with TIL as mediator.A high POS will further strengthen subordinates' trust in serving leaders.Furthermore, it will effect their behavior in playing extra roles.Based on these arguments, the researcher formulates hypothesis 4 as follows: Hypothesis 4: POS moderates the positive effect of SL on OCB mediated by TIL.

Procedure and Sample
This study uses a quantitative approach.The method of collecting data uses an online questionnaire filled in by the respondents themselves.The determination of the number of samples refers to Hair et al. (2014) who say that the rules of thumb in determining sample size are recommended 15: 1 from the research variable.A total of 238 respondents' data can be processed in this study.The number of respondents specified has met the requirements.
This study uses non-probability sampling, namely purposive techniques sampling, where respondents will be determined based on certain criteria (Cooper & Schindler, 2014).Determination of criteria is based on research needs, namely the period of respondents working in organizations of at least one year.This is done to ensure that the respondents are familiar with the leadership and scope of work.Respondents in this study were those who worked for companies spread throughout Indonesia (Java, Sulawesi, Kalimantan, Sumatra, Papua, and other small islands).Determination of sample locations aims to generalize findings especially in the collective cultural context (Butarbutar et al., 2010).

Measurement
SL is measured using measurement instruments from Van Dierendonck and Nuijten (2010) consisting of eight dimensions.These eight dimensions have reflected the six key characteristics of SL (Van Dierendonck, 2011).SL measurement consists of 30 question items.
OCB was measured using an instrument developed and validated by Lee and Allen (2002), where the instrument was designed to test individual (OCB-I) and organizations (OCB-O).
The development of instruments from Lee and Allen was also referred to by previous researchers namely Walumbwa et al. (2010).Consistent with the research of Walumbwa et al. (2010), this study will treat OCB as unidimensional.
TIL is measured using an instrument from McAllister (1995) consisting of 11 (eleven) statement items.POS was measured using instruments developed from Eisenberger (1986) consisting of 17 items.The four variables in this study used a 5-point Likert scale, starting from 1 which indicates strongly disagree to 5 which means strongly agree.

Results
The researcher tested construct validity using confirmatory factor analysis (CFA) with the varimax rotation method.The standard factor loading value used is 50.5 (Hair et al., 2014).However, before carrying out the factor analysis, two conditions must be met, namely the Kaiser-Meyer-Okin (KMO) value >0.5 and Bartlett's Test value with a significance value <0.05 (Hair et al., 2014).
In the first round of testing, the KMO value shows a number of 0.933 and Bartlett's Test is significant at 0,000.However, there were 13 items from 74 question items that did not meet the validity test requirements and were finally issued in the analysis test.Furthermore, in the second round, the KMO value is 0.945 with Bartlett's Test significant at 0,000.The results of the second round analysis show 61 items have met the validity test.However, what is unexpected in the results of this analysis is that SL and TIL variables are consistently grouped on the same factor.Statistically, these results illustrate the same (identical) answer pattern of respondents regarding SL and TIL.The results of the CFA test illustrate that there are similarities between the two constructs (SL and TIL).

Reliability
In this study, the reliability test was carried out using the Cronbach's Alpha method with a minimum value of 0.6 (Hair et al., 2014).The Cronbach Alpha value of the reliability test results showed a SL score (0.952); TIL (0,948); OCB (0.883); POS (0,936).These results indicate that the four variables meet the reliability requirements.

Descriptive and Correlation
Table 1 shows the results of descriptive and correlation testing.Based on these results it is reported that the average respondent has a high response, namely the mean value above number 3. The mean value of the highest reported is the OCB variable (3,820); TIL (3,684); SL (3,612);and POS (3,129).The value of the correlation also reported from the highest is the SL variable with TIL (r = 0.879); SL with POS (r = 0.595); OCB with POS (r = 0.555); TIL with POS (r = 0.554); SL with OCB (r = 0.434); and TIL with OCB (r = 0.377).
Based on the correlation value between variables in Table 1 it is reported that SL and TIL have the highest correlation value.These results corroborate the results of the factor analysis test which reports that SL and TIL converge on the same factor.In other words, the high correlation value between SL and TIL (reaching 87%) indicates SL and TIL are the same construct.

Result Hypothesis 1
Hypothesis 1 which states that SL has a positive effect on OCB.Table 2 shows that SL variables have a positive and significant effect on subordinate OCB (β = 0.434; t = 7.400; p <0.001).This result shows that hypothesis 1 is supported.

Result Hypothesis 2
Hypothesis 2 states that perceived organizational support moderates the effect of SL on OCB.Table 3 shows that SL variables have a significant effect on OCB (β = 0.434; t = 7.400; p <0.01) at stage one.Furthermore, the second stage reported a significant POS variable on OCB (β = 0.459; t = 6.877; p <0.01).The third stage reported that the interaction of SL and POS variables was significant for OCB (β = 2.170; t = 5.365; p <0.01).The test results of the three stages show the fulfilment of moderation requirements.Thus, it can be concluded that hypothesis 2 is supported.

Results Hypothesis 3 & 4
In contrast to the two previous hypotheses, hypothesis 3 and hypothesis 4 are reported to be not supported even without performing regression testing.The argument used in explaining hypotheses 3 and 4 will refer to the results of validity tests reported in the current study.The results of the validity test report that the SL and TIL variables group on the same factor.As a result, testing hypotheses 3 and 4 is not relevant for further data analysis.This is because hypothesis 3 and 4 of its nature will treat testing of SL and TIL variables as different constructs, while statistic results (validity test) report both as the same construct.Methodologically, it is not relevant to continue the testing phase of the SL and TIL data analysis separately as the model proposed.

Discussion
The results of testing hypothesis 1 state that SL has a positive effect on OCB supported.This finding reinforces that leadership styles that focus on the human aspect (people centered) encourage extra roles from members of the organization.This logic is in accordance with the theory of social learning, where a leader in the organization is expected to have a large effect in the social sphere.In addition, social exchange theory is also relevant in explaining support for hypotheses 1.A subordinate who perceives the leader to provide good benefits, then they will improve their performance as a form of reward to the leader.
The results of testing hypothesis 2 namely POS moderating the positive effect of SL on OCB are reported to be supported.These results support the argument that was built that contextual factors play a role in strengthening and weakening the effect of leadership style on the behavior of subordinates.When organizational members perceive that an organization supports their welfare, it further strengthens its perception of leaders who implement servant leadership in influencing their extra-role behavior (OCB).These results are in line with contingency theory that there are certain context factors that strengthen the effect of leaders on the behavior of their subordinates.These findings are also in line with the results of a study from Vondey (2010) which reported that organizational factors could moderate the positive effect of SL on OCB.
The results of testing hypothesis 3 which state that TIL mediates the effect of SL on OCB are reported to be unsupported.The assumptions built in the preparation of hypothesis 3 are based on recommendations from previous studies that trust mediates the effect of SL on OCB (Dixon, 2013;Ehrhart, 2004;Zehir, 2013;Bambale, 2014).The results of empirical studies have reported that SL is an antecedent of TIL (Joseph & Winston, 2005;Sendjaya & Pekerti, 2010;Chatbury et al., 2011).TIL was also reported to mediate the effect of SL on OCB (Trivers, 2009;Williams, 2012;Abid et al., 2015).AET (Weiss & Cropanzano, 1996) who holds that positive stimulus from leaders will effect positive attitudes and have positive behavioral effects.The argument directs the support that SL and TIL can stand independently as different constructs.Unexpectedly, the results of this study do not support the assumption that was built.
In explaining the unsupported hypothesis 3, researchers refer to the results of factor analysis where items SL and TIL group on the same factor.In addition, it also refers to the results of the correlation between SL and TIL which shows a very strong correlation value (see Table 1).The researcher suspects that the role of TIL as the mediator in the effect of SL on OCB is not supported due to the existence of constructive similarities between SL and TIL.Therefore, testing TIL in one model with SL as the model proposed in the current study is less able to provide effective results.
The majority of researchers (i.e.Liden et al., 2008;Sendjaya et al., 2008;Van Dierendonck & Nuijten, 2010) in the SL field did not include TIL as a dimension of SL.This means that the allegations related to construct similarities between SL and TIL have not been the concern of researchers in the field of SL studies.On the other hand, the results of research that indicate the existence of construct similarities between SL and TIL have also been suspected by a number of empirical studies.For example, Reinke (2003) in the results of his research argues that SL is not different from TIL because the correlation value between the two is so high that it is feared that SL and TIL explain the same thing.This opinion refers to Lewicki & Bunker (1996) who argued that leadership and trust are complementary concepts, where the concept of leadership cannot be separated from the concept of trust.In line with that, based on the literature review conducted by researchers related to empirical studies focusing on developing SL measurement instruments, there is one literature from Dennis & Bocarnea (2005) that incorporates elements of trust as one of the dimensions of SL.Thus, it can be concluded that there is no agreement regarding the construct of SL and TIL.As a result, the use of TIL and SL variables in one research model is also still a debate whether TIL is a separate variable from SL or it is an element of SL itself.Therefore, it is necessary to carry out further studies related to the findings of the similarity of SL and TIL constructs from the results of this study.
Another logical argument that can explain is not supported by hypothesis 3 because there is an effect of socialcultural context factors that are not considered.This argument is supported by the results of comparative cultural research conducted by Casimir et al. (2006).His findings report that TIL mediates the effect of leadership style on employee performance in a cultural context characterized by individualism (Australia).Meanwhile, in the cultural context that is characterized by collectivist (Chinese), TIL is reported to not mediate the effect of (transformational) leadership style on employee performance.One of the findings points out that TIL is easier to develop in individual cultures than collectivist cultures.In line with that, Chen X.P. et al. ( 2014) conducted a study on a collectively characterized (Chinese) culture also reported that affective trust (one of the dimensions of TIL) did not mediate the effect of paternalistic (benevolence and morality) leadership on subordinate OCB, this is because Chinese ideology emphasizes the importance of maintaining human relations.Subordinates tend to assume that maintaining interpersonal harmony with others (including leaders) is part of their duties without requiring an emotional approach.Thus it can be assumed that TIL is not supported as a mediator because there is an effect from the social-cultural context which is not a concern in the current research.
Development of hypothesis 4 refers to a number of empirical support from previous studies.A number of researchers report the positive effect of SL on OCB (Dixon, 2013;Mathur & Negi, 2014).Meanwhile, Harwiki (2013) reported insignificant effect on certain organizational contexts.The inconsistency of previous studies provides a research gap to examine the role of moderation in the effect of SL on OCB but remains consistent with the important role of TIL in the SL mechanism towards OCB (as the construction of hypothesis 2).However, the assumption built on hypothesis 4 states that the POS will moderate the effect of SL on OCB with TIL as a mediator stated to be unsupported.That is, the POS cannot strengthen/weaken the effect of SL on OCB through TIL.
Not supported by hypothesis 4 can be explained by arguments used in explaining the unsupported hypothesis 3. The results of factor analysis which reported that SL and TIL have constructive similarities can also effect the effectiveness of the role of TIL as a mediator in the model built.This is because SL and TIL are perceived to be identical (similar) so that they tend to be difficult to distinguish especially from the point of view of subordinates as respondents (Reinke, 2004).Although it is assumed that POS can moderate the model, but because of SL and TIL are perceived to be the same, TIL as the mediator does not have a significant effect.Thus, POS does not act as a moderator in the indirect effect of SL on OCB through TIL.
The contingency theory and AET are less able to explain the results of hypothesis 4. In contrast to the logic of contingency theory used in formulating hypothesis 2 without the existence of explanatory variables (mediator).Explanation of the use of the theory in different mechanisms further reinforces the notion that testing of SL and TIL in the same model is less able to provide effective results.

Conclusion
Current research provides an understanding of effective mechanisms in testing the role of leaders in subordinate behavior by considering contextual roles.The results show that leadership styles that focus on the needs of subordinates encourage the subordinate prosocial behavior.In addition, organizational support is also important in strengthening the effect of leaders (SL) on subordinate positive behavior (OCB).Another finding in this study is that there are indications of construct similarities between SL and TIL.Therefore, testing SL with TIL in the same set of models needs to consider the potential for overlap.
The results of this study contributed to the side of academics and practitioners.On the academic side, it is expected to provide an empirical addition to the effect of SL on OCB.In addition, it provides an understanding that organizational support has an important role in strengthening the leader's positive effect on the behavior of subordinates.This study also indicates the existence of constructive similarities between SL and TIL which will be useful in the leadership literature, especially SL.Finally, this study provides a generalization of better results by taking samples from various regions in Indonesia.Previous research on SL in Indonesia only took place in certain locations which were then generalized at the state level (Butarbutar et al., 2010;Pekerti & Sendjaya, 2010).Regarding of the practitioners, the results of this study are expected to be a recommendation for organizational leaders in carrying out effective leadership.
This study has limitations that are useful for the development of further research.First, the measurement of variables is based on the perception of subordinates (self-report) to trigger the occurrence of the common method bias (Podsakoff et al., 2012).Future research is expected to take the data not just from one source for more accurate and comprehensive results.Second, the results of the study indicate the existence of constructive similarities between SL and TIL where this has not been the focus of current research.Future research is expected to conduct research that specifically examines construct similarities between SL and TIL.Third, one argument in explaining that TIL is not supported as a mediator in this study is that social, cultural factors are not considered.The next study is expected to be able to consider the factors of the social-cultural context in examining the role of TIL as a mediator in the effect of SL on OCB.