The Role of Volunteer Participation and Person-Organization Fit in the Relationship between Motives and Psychological Well-Being

(1) Background: Studies have been limited in explaining how volunteering acts as underlying mechanisms that associate the antecedents and outcomes of volunteering. This study aims to investigate whether volunteer participation mediates the relationship between motives (self-oriented and other-oriented) and psychological well-being, and further whether person-organizational (PO)-fit moderates the relationship between motives and volunteer participation. (2) Methods: Data were collected from full-time employees in organizations in South Korea using a self-administered instrument. To test the hypotheses, hierarchical regression analyses and path analyses were conducted. (3) Results: Volunteer participation showed a significant mediating effect only for the relationship between other-oriented motives and psychological well-being. PO fit showed a significant moderating role, and further analysis revealed that the mediated moderation of PO-fit was significant. (4) Conclusions: Results suggest that employees with other-oriented motives and PO fit were more likely to participate in volunteer activities, which then increased one’s psychological well-being. Findings provide insights for HR practitioners regarding employee volunteering programs.


Introduction
Employee volunteering has become an essential facet for sustainable organizational development in that employee volunteering has been found to be beneficial for both employees and organizations [1]. Personal outcomes of employee volunteering are related to satisfying individual needs and increasing general well-being [2]. Studies have demonstrated that employee volunteering leads to the fulfillment of a variety of individual higher-order needs [3,4] and experiences of greater happiness and psychological well-being [5]. Also, employee volunteering has been found to increase positive organizational outcomes, such as job satisfaction, organizational pride, commitment, and citizenship behavior [6]. In addition to the outcomes of employee volunteering, scholars have suggested the pertinence of antecedents influencing employees' decisions to volunteer [7]. Subsequently, research has found individual-level antecedents, such as personality traits and demographics, and organizational-level antecedents, such as organization size and organizational support to influence employee volunteering [8,9].
Rodell et al. [2] conceptualized an integrative framework that delineates the antecedents of volunteering, such as organization characteristics (e.g., financial support, employer recognition), workplace characteristics (e.g., job design, work context), and individual factors (e.g., personality, motives, identity), and the consequences of volunteering, such as personal outcomes (e.g., well-being, Figure 1 shows the hypothesized research model. Sustainability 2020, 12, x FOR PEER REVIEW 3 of 12 Studies have been well established for the relationship between volunteering and well-being. Snyder and Omoto [27] proposed the volunteering process model, which consists of precedents, experiences, and consequences of volunteerism, and Binder and Freytag [28] stated that subjective well-being should be classified as one of the consequences of volunteering. Research has consistently found volunteering to increase well-being [28][29][30][31]. Therefore, understanding the relationships between motives and volunteering with well-being and the hypothesized relationships between motives and volunteer participation, we propose the following: Hypothesis 1a. Volunteer participation will mediate the relationship between self-oriented motives and psychological well-being.
Hypothesis 1b. Volunteer participation will mediate the relationship between other-oriented motives and psychological well-being.

The Moderating Role of Person-Organization Fit
Person-organization (PO) fit refers to the compatibility between employees and their organization [32]. When an employee's values and the organization's values are similar, employees tend to have positive workplace attitudes and behaviors toward the organization [10]. Meglino et al. [33] argued that when employees have similar values with their organization, they are more likely to interact more efficiently with their organization, reduce uncertainty while increasing satisfaction, commitment, and identification toward their organization. Subsequently, studies have found PO fit to result in positive associations with numerous workplace outcomes, such as job satisfaction, organizational commitment, and job performance, while negatively related to turnover and deviant behavior [34,35].
Studies have found PO fit to be related to organizational citizenship behavior [32,36]. When employees believe they have congruent values with their organization, they will be more likely to constructively contribute toward the organization and engage in extra-role behaviors, such as participating in volunteering activities. In this regard, when employees perceive similar values, PO fit can further strengthen the positive effects of motives on volunteer participation; thereby, we propose the following: Hypothesis 2a. PO fit will moderate the relationship between self-oriented motives and volunteer participation as PO fit will strengthen the relationship. Hypothesis 2b. PO fit will moderate the relationship between other-oriented motives and volunteer participation as PO fit will strengthen the relationship.

Sample
Data were collected from full-time employees in numerous organizations using a self-administered instrument in South Korea. Organizations for the study were chosen based on whether they engaged in employee volunteering programs. The organizations operated a variety of employee volunteering programs within their community, such as assistance programs for people with disabilities and educational programs for low income families. Questionnaires were sent to 400 employees by mail, and 312 completed questionnaires were returned (78% response rate). Out of the 312 questionnaires, 309 were usable as cases with missing data were discarded.
The average age of respondents was 33.6 years old (S.D. = 7.73), and the average tenure was 8.8 years (S.D. = 7.7). The majority of the respondents were male (53.1%) and had a college degree (55.7%). In terms of organizational position, 57% of the respondents were entry level, 20.4% were assistant managers, and 14.9% were managers.

Measures
As recommended by Brislin [37], all of the measure items for the questionnaires were translated into Korean and later back-translated into English to verify the quality of the translations. The items were measured with a 7-point Likert scale (1, "strongly disagree", to 7, "strongly agree").
Self-oriented motives were measured with Cronelis, Van Hiel, and De Cremer's [37] 3-item scale. Sample items are: "Volunteering makes me feel good about myself" and "I hope to achieve something for myself through volunteering." The reliability of the scale was 92.
Other Volunteering participation was operationalized as the degree to which employees have decision making in selecting different types of volunteering activities and participation in volunteering activities. Sample items are: "My colleagues and I work as a team on volunteering activities" and "My colleagues and I have ample opportunity to suggest volunteering activities," The reliability of the scale was 91.
Psychological well-being was measured with the Mental Health Continuum (MHC-SF) [41]. The 6-item scale was derived from one of the psychological well-being facets from the MHC-SF. Sample items are: "I like most parts of my personality" and "I am quite good at managing the responsibilities of my daily life." The reliability of the scale was 84.
Since the surveys were all self-rated, and the data were cross-sectional, we conducted Harman's single-factor test for possible common method biases. The results explained 37.09% of variance, which implies that there was no dominant factor that explained a majority of the variance. Thus, common method variance was not a serious issue. Table 1 shows the means, standard deviations, and correlations for the research variables.

Results
To validate the distinctiveness of the study variables, confirmatory factor analysis (CFA) was conducted. Table 2 depicts that the hypothesized five-factor model (χ 2 (109) = 183.39, GFI = 0.93, TLI = 0.98, CFI = 0.98, RMSEA = 0.05) showed a better fit compared to the other models. To test the hypotheses, hierarchical regression analyses and path analyses were conducted with SPSS 24 and Mplus 8. The demographic variables were all included in the analyses. First, we tested the hypothesized model in Figure 1, and the model resulted in a poor fit (CFI = 0.879, TLI = 0.096, RMSEA = 0.213). Hence, the model was revised referring to the modification indices based on previous research suggesting that motives had significant effects on well-being [18,[24][25][26]. The revised model included direct paths from each type of motive to psychological well-being and resulted in a perfect fit as it was a saturated model.
To test the mediation effects as posited in Hypothesis 1a and 1b, the delta method and bootstrapping were used, and both symmetric and bias-corrected bootstrap 95% confidence intervals were reported as recommend by MacKinnon [42] and Muthén and Muthén [43]. As shown in Table 3, the indirect effect of volunteer participation was not significant for the path from self-oriented motives to psychological well-being as the bootstrapped 95% CI around the indirect effect consisted of zero (−0.07, 0.09), thus not supporting Hypothesis 1a. In contrast, the mediating role of volunteer participation was significant for the path from other-oriented motives to psychological well-being as the bootstrapped 95% CI around the indirect effect did not consist of zero (0.06, 0.21) and the proportion of the total effect mediated was 66.3%; thus supporting Hypothesis 1b. Hypothesis 2a and 2b posited that PO fit will moderate the relationships between self-oriented motives and other-oriented motives with volunteer participation, respectively. The moderation hypotheses were tested using Aiken and West's [44] recommended techniques as the predictor, and moderating variables were first mean-centered before conducting the regression analyses. As seen in column 3 in Table 4, PO fit did not moderate the relationship between self-oriented motive and volunteer participation (β = −0.07, ns) while significantly moderating the relationship between other-oriented motive and volunteer participation (β = −0.24, p < 0.01). Subsequently, the interaction effects were plotted at plus/minus one standard deviation from the mean [44]. As depicted in Figure 2, PO fit enhanced the positive effects of other-oriented motives toward volunteer participation. Therefore, Hypothesis 2a was not supported, while Hypothesis 2b was supported. Table 4. Regression results for moderation.

Volunteer Participation
Step 1 Step 2 Step 3 Hypothesis 2a and 2b posited that PO fit will moderate the relationships between self-oriented motives and other-oriented motives with volunteer participation, respectively. The moderation hypotheses were tested using Aiken and West's [44] recommended techniques as the predictor, and moderating variables were first mean-centered before conducting the regression analyses. As seen in column 3 in Table 4, PO fit did not moderate the relationship between self-oriented motive and volunteer participation (β = −0.07, ns) while significantly moderating the relationship between otheroriented motive and volunteer participation (β = −0.24, p < 0.01). Subsequently, the interaction effects were plotted at plus/minus one standard deviation from the mean [44]. As depicted in Figure 2, PO fit enhanced the positive effects of other-oriented motives toward volunteer participation. Therefore, Hypothesis 2a was not supported, while Hypothesis 2b was supported.   Furthermore, as one of the moderation hypotheses was supported, a supplementary analysis was conducted to test the research model for mediated moderation. Using the macro PROCESS (Model Sustainability 2020, 12, 330 7 of 12 7), Table 5 shows that the bootstrapped results around the indirect effect did not contain zero (−0.09, −0.03); thus, mediated moderation was supported. Therefore, suggesting that PO fit enhanced the positive effects of other-oriented motives and also indirectly influencing psychological well-being. Bootstrap size = 5000. LL = lower limit: CI = confidence interval; UL = upper limit.

Discussion
This study aimed to examine the relationships between motives, PO fit, volunteer participation, and psychological well-being. Most studies on volunteering have been conducted in Western countries; however, scholars have argued that cross-cultural differences can have culture influences on how individuals perceive volunteering [45]. For example, Finkelstein [46] demonstrated that other-oriented motives are strongly related to collectivism in which individuals are motivated by group interests, while self-oriented motives are closely linked with individualism. Accordingly, self-oriented motives may have been unrelated because this study was conducted in South Korea, which has been described as one of the most collectivistic cultures [47]. Korea is a collectivistic society where values are emphasized on the collective such as an organization and its norms and on maintaining harmonious interpersonal relationships [48]. Furthermore, collectivists do not prefer to display their personal accomplishments [49]. Thus, other-oriented motives were found to be significantly related to volunteer participation, while self-oriented motives were not significantly related.
Employees that perceive similar values and beliefs with their organizations tend to interact more efficiently with their organizations. Consequently, studies have found PO fit to reduce uncertainty and turnover intentions while increasing satisfaction, identification, and commitment toward their organization [50,51]. Consistent with extant literature, the study found PO fit to be related to volunteering participation, thus suggesting that employees who share organizational values will be more likely to constructively contribute toward their organization, such as engaging in corporate volunteering activities. Regarding the moderating results, PO fit did not moderate the relationship between self-oriented motives and volunteer participation, while it significantly moderated the relationship between other-oriented motives and volunteer participation. Employees with congruent values with their organizations strengthened the positive effects of other-oriented motives on volunteering participation. Thus, as individuals are active in how they respond with their situations, PO fit enhances the effects of other-oriented motives that allow employees to further engage in constructive behaviors such as volunteering as they perceive the situation to be compatible with themselves [10]. However, a surprising finding was that both high and low levels of PO fit increased volunteer participation and that low levels of PO fit increased substantially in comparison to high levels of PO fit. This finding can be explained due to the collectivistic nature of Korean society as collectivism emphasizes the norms, beliefs, values, and the interests of the collective [52]. As a result, employees that felt they had less congruent values with their organizations may have actively participated in volunteering programs to establish, maintain, or restore positive organizational relationships and fit in with other employees.
Volunteer participation was found to mediate the relationship between other-oriented motives and psychological well-being. Other-oriented motives impacted psychological well-being only through volunteer participation, which suggests the valuable effects of volunteering programs for organizational members in regard to improving individual well-being. In addition, the study found self-oriented motives to have a significant direct effect on psychological well-being, and our findings were consistent with previous research identifying the positive associations between volunteers' self-oriented motives and psychological well-being [53]. Having self-oriented motives indicates that people are trying to improve themselves [18] and readiness for self-improvement is known to be positively associated with Sustainability 2020, 12, 330 8 of 12 well-being [54]. Regarding other-oriented motives, previous research indicated mixed results for the relationship between other-oriented motives and psychological well-being [18,55]. Subsequently, the study did not find other-oriented motives to be significantly related to psychological well-being.
The significant relationship between volunteering participation and psychological well-being confirms extant literature [28,31] and stresses the importance of providing accessible opportunities for volunteering so that it can increase the well-being of organizational members. Moreover, we found that volunteer participation mediated the interaction between other-oriented motives and PO fit on psychological well-being. Therefore, volunteer participation was an underlying mechanism through which the interacting effects influenced an individual's psychological well-being. This finding suggests that employees with other-oriented motives and PO fit were more likely to participate in volunteer activities, which then increased one's psychological well-being.

Implications
The study proposed the mediating effects of volunteer participation for the relationship between motives and psychological well-being and the moderating effects of PO fit for the relationship between motives and volunteer participation, which extends previous literature on employee volunteering. First, in alignment with Rodell et al.'s [2] conceptual framework, the study contributes to literature as volunteer participation was an underlying mechanism that associated individual motives and psychological well-being, although only other-oriented motives were found to be significant. Second, the results showed that self-oriented motives had a direct effect on psychological well-being; thus, consistent with prior studies [53,54]. Third, PO fit was found to moderate the relationship between other-oriented motives and volunteer participation. This finding adds to literature as the interaction between other-oriented motives, and PO fit results in increased participation in volunteering activities as well as individual well-being. Additionally, this finding also confirms extant literature about the positive moderating effects of fit perceptions on employee outcomes [56,57]. Last, as the study found PO fit to moderate the mediated research model, this further contributes to theory as this finding suggests that certain boundary conditions can foster the positive effects of motives and, moreover, explaining that perceptions of PO fit indirectly influences psychological well-being.
The study provides insights for HR practitioners regarding employee volunteering programs. Our findings suggest that employee volunteer participation can be a driving force for promoting psychological well-being. As volunteering positively influences well-being, an employee's positive psychological states can further result in other positive organizational outcomes. Therefore, the study prompts practitioners to consider the strategic value of employee volunteering as a means of creating positive organizational outcomes by promoting psychological well-being. Our findings also show that PO fit may promote employees to participate more frequently in volunteer activities. Thus, organizations should communicate organizational values with their employees to promote perceptions of organizational fit through various socialization and training programs and interpersonal relationships such as leaders [58,59].

Limitations and Future Directions
Reviewing our findings, there are several limitations to address. First, the study did not consider complex motives, assuming volunteering is driven by self-oriented or other-oriented motives. The functional approach argues that volunteering simultaneously serves multiple functions for an individual [15] and that volunteering can be triggered by a combination of both self-oriented and other-oriented motives. Hence, it would be constructive to examine in more detail how motives drive individuals to volunteer and under what boundary conditions can further explain the relationship between motives and volunteering.
Second, the study utilized one dimension of well-being, psychological well-being, from the original multi-dimensional scale developed by Keyes [41]. The scale includes three dimensions, emotional, social, and psychological well-being, and the level of overall well-being is estimated by summing up the three dimensions. Social well-being, in particular, is a dimension that is closely related to volunteer participation since the scale contains items such as social integration and contribution. In this aspect, using the three dimensions of well-being can also give us a clearer picture of the relationship between well-being and volunteering as well as the influences of self-and other-oriented motives on each dimension of well-being.
Third, the study used a convenience sampling method; therefore, the results may be generalized to the sample and may not fully represent the population. Thus, future studies should include larger and more diverse samples to improve the generalization of the findings. Last, as the study was conducted in Korea, the results may not be generalizable. Cultural characteristics can significantly influence individual motives and participation in volunteer activities, especially as our study found other-oriented motives to affect volunteering rather than self-oriented motives.
As studies have generally focused on the positive outcomes of volunteering, future studies should also examine if employee volunteering can have detrimental effects on employees. Rodell et al. [2] mentioned that there can be possible risks of volunteering and research should investigate whether volunteering can be a job stressor and result in negative organizational outcomes such as reduced levels of job performance. For instance, Kiviniemi, Snyder, and Omoto [60] found volunteering to increase stress and lower satisfaction; however, their study was not conducted on corporate employees, but it still can shed light on whether corporate volunteering can also have negative outcomes. Furthermore, volunteering may also have a curvilinear relationship with workplace outcomes. When employees volunteer too much, it may result in negative outcomes. Numerous studies in organizational behavior have found curvilinear outcomes such as in the relationship between personality traits and job performance [61] and leader-member exchange and stress [62].
Employee volunteering programs are vital components of employee well-being. As studies have found numerous positive effects of volunteering, this study also is consistent as volunteering was found to improve an individual's psychological well-being. In addition, PO fit was found to mediate the moderate study model, which suggests that perceptions of fit have positive indirect effects on psychological well-being. Moreover, the study contributes to literature as volunteer participation was an underlying mechanism that associates individual facets and outcomes.