Integrating OCBE Literature and Norm Activation Theory: A Moderated Mediation on Proenvironmental Behavior of Employees

Abstract

Research lacks a solid understanding of the relational patterns between intrapersonal and organizational determinants to promote proenvironmental behavior. In this study, I investigated the effects of employees’ intrapersonal and perceived organizational determinants on voluntary proenvironmental behavior of employees (VPBE) from an integrative moral perspective. While primarily building on insights from norm activation theory and research on organizational citizenship behavior for the environment (OCBE), I developed a framework and empirically analyzed how interactions between ascriptions of environmental responsibility, perceptions of proenvironmental work climates, and affective organizational commitment influence VPBE. The findings show that even employees (in this study: student workforce) with little sense of responsibility towards nature can be subtly encouraged to practice VPBE. I discuss the findings against the backdrop of integrated and introjected norms and provide managerial advice. The study contributes to a theoretical broadening of the norm activation theory in workplace contexts and advances our knowledge of conditional effects and normative mechanisms underlying VPBE.

1. Introduction

Organizations are pressured to adopt green management practices [1] to play a significant role in promoting sustainable development since their operations cause various negative environmental impacts, such as contaminating emissions and pollution and overuse of natural resources [2,3]. Despite many organizations initiating strategies and programs to improve their environmental performance, even those certified by environmental management standards are not immune to poor implementation [4]. To transform organizations’ sustainable development strategies into concrete practices and eventually improve environmental performance [5,6], it is essential to encourage employees, i.e., actors who have to implement environmental measures within organizations [7], to behave pro-environmentally [8,9,10,11].

In the workplace, the obstacles to performing proenvironmental behaviors are numerous [12] and it is difficult for organizations to fully direct each employee’s behavior toward the desired proenvironmental direction [3,13]. One option is to include proenvironmental tasks in formal job descriptions. However, it is not possible to cover every single aspect of proenvironmental behavior in such descriptions. Therefore, employees’ non-obligatory and informal behavior in particular contributes to corporate greening by either reducing the organization’s environmental impact or benefiting the environment [14,15].

While making use of established behavioral models, such as the Theory of Planned Behavior [16], research on such voluntary proenvironmental behavior of employees (VPBE) strongly builds upon knowledge of voluntary proenvironmental behavior in the private sphere (such as recycling or energy-saving of households). Unfortunately, researchers who use this theoretical stream often posit that proenvironmental behavior is mainly driven by self-interest and the rational evaluation of behavioral consequences [17]. In line with other recent workplace studies on proenvironmental behavior (e.g., [18]), I argue that such an approach is only partially applicable to the corporate context and needs to be complemented by a set of normative and contextual variables. First, as has been shown by extensive research on organizational citizenship behavior for the environment (OCBE [19]), organizational determinants also influence voluntary proenvironmental behavior (e.g., [8,14,20]). Thus, we need to consider aspects such as perceived organizational or colleague support [21] as well as employees’ identification with or affective commitment to the organization [22]. Second, several studies from the private sphere of voluntary proenvironmental behavior support the idea that norm activation may be important for various proenvironmental behaviors [23,24,25]. Specifically, personal norms are assumed to be a crucial predictor of proenvironmental behavior in the business context [26,27,28]. From a voluntary perspective, however, research still lacks empirical evidence on the applicability of norm theories in the corporate sphere [29]. Consequently, the scarcity of insights on the interplay between several intrapersonal and organizational determinants limits the development of evidence-based managerial interventions to effectively leverage VPBE [10,30].

The purpose of the present research is twofold. First, I broaden the knowledge of intrapersonal normative processes of VPBE by testing the importance of interdependencies (i.e., moderation effects) between theoretically derived determinants of proenvironmental personal norms, such as proenvironmental work climate and affective organizational commitment. This helps scholars and managers alike to understand the normative mechanisms underlying VPBE and, furthermore, highlights how different degrees of internalization of norms, i.e., integrated and introjected norms [31], affect VPBE. Second, contrary to the excessive use of the Theory of Planned Behavior (cf., the meta-analyses by [10,32]), thus far, the norm activation model has only rarely been applied to study proenvironmental behavior in the corporate context, and VPBE in particular (notable exceptions being [24,25]). Therefore, the intricate relationships among key variables within the norm activation model are still not fully clear [24]. This study aims to clarify these associations and shows how the norm activation model can be adapted to fit the corporate context for voluntary proenvironmental behavior.

Building on insights from norm activation theory [33,34] and research on organizational citizenship behavior for the environment (e.g., [15,35,36]) that both serve as theoretical lenses for the present study, I developed a synthesized model to explain the emergence of VPBE. The results reveal that investigating the motivational antecedents of VPBE from a normative perspective is a valuable research endeavor, particularly if conditional effects are considered. I discuss the findings in light of previous empirical research on VPBE and enrich the scarce empirical literature on interactions between organizational and individual determinants of normative processes. Furthermore, I derive theoretical and practical implications as well as avenues for future research.

2. Theoretical Background and Hypotheses

2.1. Conceptualizing Voluntary Proenvironmental Behavior

Proenvironmental behavior can be understood as a complex multi-layered concept and an umbrella term for various behaviors that either harm the environment as little as possible or benefit the environment [37,38,39]. In pursuit of a better understanding of proenvironmental behavior and its determinants, several theories and models have been applied to identify factors that promote such behavior [40,41,42,43].

The majority of studies in the environmental domain since the 1980s have primarily focused on proenvironmental behavior in the private and public spheres [7,44,45]. Many of these studies relied solely on intrapersonal factors [46] without considering the contextual environment or situation appropriately. Contextual factors, however, can directly affect proenvironmental behavior as well as moderate the influence of intrapersonal factors [46,47,48]. Since intrapersonal factors vary considerably among different contexts [49], insights from the private sphere or public proenvironmental behavior are unlikely to be fully transferable to the business sphere [47,50]. For instance, at home, individuals must bear the costs of resource consumption, such as energy or water, while employees at the workplace do not need to pay such costs (at least, usually not immediately). Therefore, the motivational structure of a single person to perform resource-efficient behaviors—or other forms of VPBE—might differ significantly from those in a private or public context [51], and contextual influences as well as intrapersonal determinants should be considered equally [26,52,53].

Generally, employees behave pro-environmentally when they engage in actions “that are linked with and contribute to or detract from environmental sustainability” [54] (p. 87). According to Boiral et al. [55], employees’ proenvironmental behavior comprises every action of an individual within the corporate context that aims to reduce the organization’s environmental impact. Employees’ proenvironmental behavior, thus, can be distinguished into two categories: organizationally required tasks and procedures (i.e., proenvironmental task behavior) and discretionary activities or initiatives that are neither organizationally prescribed nor rewarded by the organization [55,56]. This classification is sometimes also referred to as in-role vs. extra-role behaviors (e.g., [57]), whereby VPBE falls into the extra-role category as it is neither formalized in role descriptions, role expectations, or job requirements nor recognized in the formal reward system [3]. This means employees performing VPBE tend to preserve the environment because of the intrinsic value they assign to their natural environment, rather than just viewing proenvironmental behavior as a means to an end [58]. Therefore, VPBE constitutes employees’ supererogation toward the environment [59].

VPBE itself can be further distinguished based on its intended influence and unit of analysis: Concerning its intended influence, it can be directly or indirectly targeted toward the environment [3]. In a direct way, VPBE addresses environmental concerns, such as energy (e.g., energy savings), waste (e.g., recycling residues or separating trash), resource (e.g., saving packaging materials, paper, or water), and emissions issues (e.g., using less-polluting modes of transportation or finding sources of contaminant emissions), or—more generically—employees’ efforts to avoid harm and their involvement in initiatives. In an indirect way, VPBE does not lead to environmental improvements right away. Instead, it acts as an enabler for such improvements. Examples include making suggestions for improving the company’s environmental practices, identifying technical malfunctions with significant environmental impacts, or questioning ecologically harmful corporate practices. Considering these illustrations, VPBE’s unit of analysis can be both the individual employee and a collective, e.g., teams [60].

In sum, I conceptualize VPBE as extra-role proenvironmental behavior, which is usually integrated into the employees’ day-to-day business [3,61] and practiced to directly and/or indirectly improve individual or collective proenvironmental performance at work.

2.2. VPBE and the Case of Student Workforce

Students are usually recognized as a future source of qualified employees [62] that are, among other factors, attracted by organizations’ ecological performance [63,64]. The student workforce constitutes an increasing cornerstone of companies in Western economies [65,66,67], and employing students often results in a synergetic relationship [68] that mutually benefits both students and employers [69,70,71]. From a short-term perspective, a student workforce enables employers to reduce their costs [69,72], while at the same time enhancing an employer’s need for flexibility [65]. From a rather long-run perspective, a student workforce represents a well-educated [65] and motivated workforce, which allows employers a low-risk in-depth first look at potentially new full-time employees and future managers [69,73].

The student workforce is particularly valued for good communication and problem-solving skills [65,72], attributes which have proven beneficial to stimulate proenvironmental workplace behaviors among colleagues and subordinates (e.g., [74,75]). Such a workforce fosters “an awareness of the constant need for adaptability and creativity in a changing world” [68] (p. 41) and is, furthermore, awaited to bring new ideas into organizations [69,73]. Due to the increasing incorporation of environmental management competencies in business administration curricula, organizations are likely to benefit from the increasing environmental knowledge of their student workforce [76,77], which seems generally more willing to act in a proenvironmental fashion [78].

However, figuring out what inspires students to behave pro-environmentally is a significant area of concern on the way toward corporate sustainability [43,79]. In their recent meta-analysis of experimental studies on proenvironmental behavior, Maki et al. [80] found that positive spillover effects between proenvironmental behaviors are more likely when the individual’s intrinsic motivation is addressed. This indicates that in workplace contexts, investigating different degrees of internalized motivation could reveal varying degrees of VPBE. Consequently, VPBE of a student workforce is likely to depend on the workforce’s perception and the internalization of proenvironmental norms prevalent at the workplace.

Employers give great importance to imparting appropriate behaviors and competencies to their student workforce [81]. Moreover, research constantly finds CSR to be essential to attract students (e.g., [82,83,84]), and employers often look to convert student workforce (e.g., interns, student assistants, and student trainees) to full-time hires (e.g., [85,86,87]). As such, highlighting the relevance of corporate sustainability to the student workforce using an appropriate organizational culture [88] is also likely to pay off with regard to the future. For instance, as soon as the former student workforce that once has been encouraged to behave pro-environmentally at work—e.g., by appealing to their moral norms—converts to regular employees after completing their studies, they may become change agents for cultivating VPBE within the next generation of employees (including cohorts of a new student workforce).

Despite the increasing prevalence of the student workforce [89], it has, however, not yet received the research attention which would live up to its rising importance (e.g., [90]). The student workforce differs from regular employees in several ways, such as an above-average education in environmental management (e.g., [78]), fewer average working hours than full-time employees (e.g., [89]), and another approach to becoming embedded in the organization they work for compared with tenured employees (e.g., [91]). Notwithstanding this, the student workforce constitutes the “managers of tomorrow” and is, therefore, a crucial group of employees when it comes to improving corporate sustainability in the long run. In sum, by investigating the student workforce against the backdrop of VPBE, I acknowledge the seemingly unanimous view of the current literature that the Western student workforce economy is here to stay (e.g., [66]).

2.3. Determinants of VPBE

2.3.1. Determinants of VPBE from the Norm Activation Model

A prominent model in environmental psychology research is the norm activation model [33,34]. It is based on the assumption that individual moral considerations affect prosocial (and thus, proenvironmental) behavior [25]. Moral considerations serve as the basis for private and public sphere proenvironmental behavior [42,92], which makes the norm activation model a promising lens for examining crucial antecedents of proenvironmental behavior [23,52]. Taking moral considerations into account to achieve a better understanding of VPBE might also prove beneficial because employees’ voluntary proenvironmental behavior—like private-sphere proenvironmental behavior—is at least partially based on ethical decision making [3]. In both situations, at home and work, the person in question refrains from benefitting personally for the sake of the environment when acting pro-environmentally [92]. Put differently, by performing VPBE, employees accept additional efforts and possible inconveniences [3] that could hamper their occupational task-related behavior [50].

According to the norm activation model, personal norms embody the core element of prosocial and proenvironmental behavior [93]. Personal norms express the individual’s belief in whether a behavior is morally considered right or wrong. Once activated, personal norms are perceived as moral obligations that serve as a motivational force rather than as intentions to act [33,94]. Thus, personal norms are normative aspirations for behaving in a particular manner [33,95,96]. The basis for an individual’s willingness to adhere to his or her norms, at that point, is the awareness that violating one’s personal norms would lead to negative feelings, such as regret or guilt [33,97].

Personal norms can essentially influence different forms of proenvironmental behavior. There is empirical evidence for the effects of personal norms on general proenvironmental behavior [98,99], as well as for several specific domains of proenvironmental behavior, such as conserving resources [100,101], meat and organic food consumption [102,103], mobility behavior [104,105], and recycling or waste avoidance [106,107,108] in the private sphere. Moreover, personal norms have been found to be better predictors of actual behavior than more external social norms (e.g., [109]). When aiming to transfer these results to organizations, voluntary discretionary behavior is usually strongly influenced by personal predispositions [3]. Thus, individuals with a strong tendency to generally protect the environment are likely to show voluntary proenvironmental behavior in the workplace, too [110]. In addition to that, several studies support the assumption that personal norms positively affect individuals to perform certain proenvironmental behaviors at work (e.g., [92] for a reduction of car commuting; [111] for work-related travel mode choice; [28] for energy conservation at the workplace). Hence, I propose the following hypothesis:

Hypothesis H1.

The stronger employees’ personal proenvironmental norms, the higher the level of VPBE.

From an intrapersonal perspective, the activation of personal norms can be traced back to two additional antecedents: an individual’s awareness of consequences and his or her ascription of personal responsibility [92]. Awareness of consequences means that an individual must be aware of negative consequences that result from non-prosocial behavior. Beyond this, a person also needs to feel responsible for the resulting negative consequences, i.e., the individual’s ascription of responsibility [33,112,113]. According to the value–belief–norm theory [114,115], the influence of awareness of consequences on proenvironmental behavior is assumed to be mediated by an individual’s ascription of responsibility. In turn, such an ascription of responsibility leads to the emergence of personal norms, thus forming a fully mediated causal chain of antecedents of proenvironmental behavior [93]. In line with that reasoning, an employee’s ascription of responsibility may serve as a distant determinant of VPBE, able to activate personal norms at the workplace.

In the corporate context, an individual’s ascription of environmental responsibility can be defined as the extent to which a single employee feels responsible for the negative consequences of their own environmentally harmful behavior. Several empirical studies have shown a positive relationship between ascribed environmental responsibility and proenvironmental norms [93,107,112]. In their study on students’ car use for commuting to a university, Bamberg and Schmidt [116], for instance, found a direct effect of ascriptions of environmental responsibility on proenvironmental norms. In addition, within organizations, initial evidence seems to confirm this positive dependency between ascriptions of environmental responsibility and proenvironmental norms (for instance, when employees consider their energy-saving behaviors at the workplace [25]). This leads to the following hypothesis:

Hypothesis H2.

The stronger an employee’s ascription of environmental responsibility, the stronger her or his personal proenvironmental norms at the workplace.

2.3.2. Determinants of VPBE from an OCBE Perspective

From an employee’s perspective, a proenvironmental work climate may contribute to the emergence of personal proenvironmental norms and VPBE [117,118]. Generally, a proenvironmental work climate captures employees’ beliefs about how they see themselves supported and appreciated by their work environment for their engagement in proenvironmental activities [117]. The concept of a proenvironmental work climate emerges from two closely related conceptual antecedents, the psychological work climate and the concept of perceived organizational support, both of which have been previously related to the environmental domain.

On the one hand, the concept of psychological work climate represents an employee’s perception of the work environment [119,120], which reflects the individual’s experiences within an organization [121] and his or her consequent beliefs about the organization [25,122]. Against the backdrop of environmental considerations, notions of “green work climate perceptions” [6,117], “perceived organization’s social and environmental responsibility” [123], “green psychological climate” [118], and “pro-environmental work climate perceptions of coworkers” [124] enriched the literature to emphasize the importance of a proenvironmental work climate to foster employees’ proenvironmental behavior [125,126]. On the other hand, the concept of perceived organizational support reflects to which extent employees believe that their efforts at the workplace are appreciated by the organization [127]. Putting employees center stage, perceived organizational support fosters positive work outcomes, such as hedonic and eudaemonic well-being (e.g., [128,129]). Related to the environmental domain, Lamm et al. [130] consequentially argued that perceived organizational support for the environment, which reflects to which extent employees believe that their proenvironmental efforts at the workplace are appreciated by the organization, is likely to spur proenvironmental behavior at work. This relationship is also backed, for instance, by Manika et al. [131], who found that perceived organizational support for the environment caused employees to adjust their energy-saving behavior.

A common underlying assumption of both antecedents (psychological work climate and perceived organizational support) is that employees can form their perceptions of a proenvironmental work climate by drawing on multiple reference points [132,133]. First, on an equitable interpersonal level (i.e., between coworkers), colleagues’ support for the environment may serve as a reference (e.g., [6,13,117]). Second, an impersonal reference point is given by organizational policies, procedures, and practices that support the environment (e.g., [130,133,134]), including CSR activities [135,136]. Third—although sometimes only implicitly—superior management may also shape employees’ perceptions of a proenvironmental work climate, either by means of interpersonal interaction (e.g., role-modeling) or through designing and declaring desired policies, procedures, and practices (e.g., [133,137,138]).

Considering the equitable interpersonal level, perceived colleague support is defined as the extent to which employees believe that their colleagues appreciate their contribution and care for their well-being [139]. It includes an evaluation of past experiences among employees at the same organizational level [140]. By forming proenvironmental norms through climate perceptions, employees become increasingly likely to follow their colleagues’ lead [124]. Thus, perceived colleague support for the environment can be defined as the extent to which employees believe that their colleagues appreciate and actively support their environmental efforts. In line with Gouldner [141]’s norms of reciprocity, employees feel personally obliged to engage in VPBE, to receive appreciation and recognition, as long as colleagues signal that environmental engagement at work is important.

Regarding superior management and the impersonal perspective, employees feel particularly morally obliged to demonstrate desired behaviors when they perceive their management as supportive [142]. In other words, such supportive climates, which act as shared perceptions and cognitions, activate employees’ norms of reciprocity [143]. Generally, managers can foster organizational citizenship behavior of employees—including VPBE [144,145]—through effective leadership (e.g., [143,146,147]). By signaling support for environmental initiatives and a certain willingness to implement new organizational practices for the sake of the environment, an organization’s senior management may help employees to calibrate themselves [148]. In other words, the more orientation toward proenvironmental behavior is given, the more likely it is that individuals act accordingly [149]. Moreover, since employees generally tend to personify organizations [127], their perceptions toward the organization may also trigger a sense of normative obligation. Therefore, following the reasoning of Eisenberger et al. [127] and Rhoades and Eisenberger [128], employees are more likely to engage in VPBE (a) if they anticipate their organization to be grateful for a strong commitment to the environment and (b) if they expect their organization to honor and recognize the socio-emotional needs of employees who voluntarily engage in corresponding behaviors. Consequently, senior management has a significant role to play. By setting the normative frame for desired behaviors through corporate mission statements and the like, superior managers bear the potential to shape employees’ perceptions of the organization as a whole [150,151] and therefore, such managers constitute an essential feature of a proenvironmental work climate.

In sum, if organizations signal the importance of environmental protection (e.g., [152]) and employees experience the proenvironmental efforts of their organization as sufficiently high, then this is likely to evoke a perceived moral obligation to conform by performing the desired VPBE [133,153,154]. I propose that the multiple features of a proenvironmental work climate positively affect employees’ proenvironmental norms at work:

Hypothesis H3.

The more supportive the proenvironmental work climate, the stronger an employee’s personal proenvironmental norms at the workplace.

Beyond environment-related factors, purely organization-related aspects, such as an individual’s organizational commitment, may also influence employees’ proenvironmental behavior in the workplace. Organizational commitment is a psychological state that connects employees to their organization [155]. This construct is multidimensional [156] and is usually composed of three sub-categories: affective, normative, and continuance organizational commitment [155,157,158]. This study focuses on employees’ affective organizational commitment because it is presumed to be the core of organizational commitment [159], and in contrast to normative and continuance commitment, affective commitment often highly correlates with organizationally desired workplace behaviors, such as organizational citizenship behavior [156].

Other than employees’ environmental commitment that causes an emotional attachment and internal obligation to preserve the natural environment [13], affective organizational commitment emphasizes an individual’s emotional attachment to and involvement in an organization [155,157]. It further comprises employees’ identification with organizational values [160]. Thus, a distinct affective organizational commitment can stimulate an individual’s desire to behave according to the goals of an organization [161]. In consequence, if organizations strive for ecological sustainability, employees who show high levels of affective commitment are more likely to behave pro-environmentally [35].

The majority of empirical studies indicate that affective commitment mediates the relationship between perceived organizational support and extra-role behaviors of employees (e.g., [162]), including proenvironmental behavior [35,44]. However, if one considers the proenvironmental work climate in particular, the relationship might not be as straightforward [50], and affective organizational commitment might rather act as a distant moderator than an immediate mediator of VPBE [163]. I assume an affective organizational commitment to reinforce the effect of a proenvironmental work climate on proenvironmental norms. On the one hand, once an organization appreciates environmental efforts and employees are affectively committed to their organization, it seems reasonable that their striving for a congruent behavior (i.e., VPBE) is enhanced [110]. More specifically, higher levels of affective organizational commitment might motivate employees to obey organizational environmental norms and perform in accordance with them [164]. On the other hand, if employees’ affective organizational commitment is low (i.e., when they have internally terminated their employment), they might not necessarily develop proenvironmental norms at the workplace. This could even happen in situations where employees’ colleagues and the organization’s senior management appreciate proenvironmental efforts or when the respective individual might generally feel responsible for his or her environmental impacts (e.g., when being situated in another context, for instance, at home or with friends).

Beyond, from a more internalized perspective of norm activation, high levels of affective organizational commitment may also reinforce positive effects on proenvironmental norms at the workplace if employees feel generally responsible for their environmental impacts. Thus, to better understand VPBE, proenvironmental norms at the workplace should be treated as being dependent on complementary relationships of employees’ environmental and organizational attachments. Following this line of reasoning, I assume affective organizational commitment to act as a moderator when it comes to explaining VPBE. Figure 1 shows the conceptual model of VPBE as well as the hypothesized relationships between its intrapersonal and organization-related determinants.

Hypothesis H4.

The effect of an employee’s ascription of environmental responsibility on personal proenvironmental norms at the workplace is positively moderated by a stronger affective organizational commitment.

Hypothesis H5.

The effect of a proenvironmental work climate on personal proenvironmental norms at the workplace is positively moderated by a stronger affective organizational commitment.

3. Methods

3.1. Sample and Participants

The purposive cross-sectional sample of this study consists of student workforce who were either employed as student assistants, interns, or student trainees at a company at the time the interview took place. Participants were undergraduate and graduate business students who voluntarily completed the questionnaire (i.e., without receiving course credit in exchange or any other incentive). A total of 189 fully completed voluntary self-report surveys were available for the analyses (66 undergraduates and 123 graduates). Of the respondents, 69.3% were women, and the respondents’ age ranged from 19 to 33 years, for an average age of 24.1 years (SD = 2.4 years).

Self-reports are often criticized for validity issues. Respondents might engage in socially desired response behavior [39,165], potentially leading to biased measurements of actual behavior [166]. Therefore, to prevent common method bias and issues related to social desirability, I followed several recommendations of Conway and Lance [167], Podsakoff et al. [168], and Podsakoff et al. [169]. In addition, I also tried to minimize social desirability beforehand by appealing to the honesty of the study participants. In the cover letter, I emphasized that there were no right or wrong answers, and the questionnaire guaranteed anonymity and absolute confidentiality (i.e., respondents did not have to reveal their names, job positions, or employing firms). Nevertheless, social desirability can be problematic even in the context of anonymous surveys [170], which is why self-reported data should be interpreted with caution [165]. However, there are also multiple important reasons in favor of self-reports. First, when it comes to self-reports of proenvironmental behavior, social desirability seems to be insignificant [50]. Second, self-reports are commonly time-saving, low-priced, efficient, easy to handle, and flexible [166,171]. Third, they enable researchers to capture behavior that would be difficult or even impossible to capture otherwise [171,172]. Therefore, self-reports are (a) often used in studies on the environmental domain [36,50,173] and (b) they serve as “the theoretically most relevant measurement method” [167] (p. 329) when it comes to employees’ perceptions, which were central to our study. Lastly, since I am not aware of any study that suggests that the emotional and cognitive processes central to the present study should differ between student workforce and other groups of employees, I deem a student workforce sample appropriate for the study’s purpose.

3.2. Measurements, Data Preparation, and Analyses

Perceptions are often more important than actual organizational actions [174]. To investigate VPBE and its intrapersonal and organizational determinants, this study relied on participants’ beliefs and perceptions of their employer’s organizational environment. In cases where no single suitable scale was available, I followed a deductive scale development approach [175] and cautiously designed scales that were subject to expert interviews and pretests to ensure internal consistency and reliability. All items were measured on a five-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree).

Despite the growing body of measurement scales for proenvironmental behavior in the workplace (cf., [10,60]), during the time of development of the survey, I did not find a composite scale for VPBE that captured (a) generic (i.e., unrelated to specific environmental sub-domains), (b) extra-role sustainable daily work performances targeted towards (c) direct and indirect influences on (d) individual and collective proenvironmental behavior. Therefore, I adapted two items from Bissing-Olson et al. [176]’s Daily proenvironmental behavior measure and one item each from Homburg and Stolberg [177]’s Indirect environmental behavior scale, Robertson and Barling [178]’s Workplace environmental-friendly behavior scale, and Kaiser et al. [179]’s Social behavior toward conservation scale to specifically measure what Francoeur et al. [60]’s taxonomy refers to as employees’ efforts in monitoring environmental impact, initiating programs and policies, lobbying and activism, and encouraging others. Despite increasing construct proliferation in organizational research [180], this study’s approach of assembling items from several measurement scales is common to many empirical studies on proenvironmental behavior in the workplace (cf., [60]), and I deem it both suitable and necessary to capture the essence of generic VPBE.

Unlike the generic VPBE measure, personal norms are best conceptualized as behavior-specific norms to explain proenvironmental behavior [181]. Although only a few studies have empirically captured multiple dimensions of proenvironmental behavior [38], the literature review of those who did reveals four prevalent thematic environmental domains: (a) resource conservation, such as saving energy and water, (b) mobility behavior, such as commuting, (c) environmentally sound consumption, such as buying locally grown products, and (d) recycling and waste avoidance (cf., Table 1). However, none of these empirical studies were conducted to capture individuals’ proenvironmental norms against the backdrop of their workplace. Therefore, for the scale of personal proenvironmental norms of employees, I adapted behavioral items from Nordlund and Garvill [98] and Whitmarsh and O’Neill [182]—two highly cited research works that targeted the domains of interest. Each item started with “I feel a personal obligation to […]”, an often-used framing to capture personal norms (e.g., [151,183]).

To measure ascription of environmental responsibility, the study built on the same four environmental domains that have been used to assess personal proenvironmental norms. These domains were then related to losses of biodiversity and greenhouse gas emissions. Each item started with “I feel jointly responsible for […]”, a framing that has been used previously for measuring beliefs of environmental responsibility [112,184,185].

When the focus is on predicting individual behavior, it is recommended to assess the proenvironmental work climate at the individual level of analysis (e.g., [124]). To capture the various reference points employees may draw on, I followed Norton et al. [126]’s call to develop a composite construct that assesses several sub-facets of a proenvironmental work climate. The derived six-item scale is based on measures adapted from Norton et al. [117]’s Green work climate perceptions scale and Banerjee et al. [150]’s Top management commitment scale.

To measure affective organizational commitment, I used three items developed by Eisenberger et al. [186]. Please refer to Table 2 for further details on the items used in this study, the composition of constructs, and corresponding measures of internal consistency.

I also controlled for age, gender, and education, which potentially impact ethical decision making, such as VPBE [187,188]. However, the parameters of two different statistical analyses (i.e., including (a) all control variables and (b) any control variables) remained almost identical, with unchanged significance levels and confidence intervals. Therefore, in line with previous research (e.g., [189]) and best practice recommendations, I did not include these control variables in the further analyses [190,191,192].

Table 1. Exemplary illustration of common environmental domains of specific proenvironmental behaviors captured in empirical studies and reviews.

		Common Domains
Author(s) (Chronological)	Scale	Resource Conservation	Mobility Behavior	Environmentally Sound Consumption	Recycling and Waste Avoidance	Further Domains
Schultz and Zelezny [193]	Self-reported proenvironmental behaviors across cultures	Conserve water Conserve energy	Public transportation	Purchase environmentally safe products	Recycling
Kaiser and Wilson [194]	General ecological behavior	Water and power conservation	Ecological automobile use	Ecologically aware consumer behavior	Ecological garbage removal Garbage inhibition	Prosocial behavior Volunteering in nature-protection activities
Nordlund and Garvill [98]	Domains of everyday proenvironmental behaviors	Energy conservation	Transportation behavior	Environmentally responsible consumption	Recycling and reusing
Kaiser et al. [195]	Forty behavior items grouped into six domains	Energy conservation	Mobility and transportation	Consumerism	Waste avoidance Recycling	Vicarious behaviors toward conservation
Whitmarsh and O’Neill [182]	Proenvironmental behavior	Energy and water use	Transport actions	Environmentally sound shopping choices	Waste behavior
Swim and Becker [196]	Environmentally friendly behavior	Energy conservation		Change in food consumption		Activism for climate change
Lanzini and Thøgersen [197]	Self-reported proenvironmental behaviors	Energy and water conservation	Public transport Biking Carpooling	Green purchasing	Recycling Saving paper	Volunteering
López-Mosquera et al. [198]	Habitual proenvironmental behaviors		Reduced car use frequency	Environmentally responsible purchase frequency	Recycling frequency
Rhead et al. [199]	Proenvironmental behavior categories	Water and energy conservation	Travel	Food	Recycling
Larson et al. [38]	Frequently studied universal actions of environmentalism and civic engagement	Water conservation Energy conservation	Environmentally conscious transportation	Green or ecofriendly purchasing	Recycling Waste reduction	Proenvironmental actions in the socio-political arena
Balundė et al. [200]	General ecological behavior	Fuel-efficient driving	Sustainable transportation modes		Recycling behavior	Environmental activism
Li et al. [53]	Review article; no single scale but categories	Energy consumption	Transport use	Purchase of green products	Recycling Waste management
Yuriev et al. [201]	Review article; no single scale but categories	Energy-saving	Traveling and commuting		Recycling	General green behaviors Other
Foster et al. [52]	Proenvironmental behavior categories	Air-conditioning Printing Drinking (to capture energy and water conservation) Computer use Light use		Sustainable shopping	Recycling

Table 1. Exemplary illustration of common environmental domains of specific proenvironmental behaviors captured in empirical studies and reviews.

		Common Domains
Author(s) (Chronological)	Scale	Resource Conservation	Mobility Behavior	Environmentally Sound Consumption	Recycling and Waste Avoidance	Further Domains
Schultz and Zelezny [193]	Self-reported proenvironmental behaviors across cultures	Conserve water Conserve energy	Public transportation	Purchase environmentally safe products	Recycling
Kaiser and Wilson [194]	General ecological behavior	Water and power conservation	Ecological automobile use	Ecologically aware consumer behavior	Ecological garbage removal Garbage inhibition	Prosocial behavior Volunteering in nature-protection activities
Nordlund and Garvill [98]	Domains of everyday proenvironmental behaviors	Energy conservation	Transportation behavior	Environmentally responsible consumption	Recycling and reusing
Kaiser et al. [195]	Forty behavior items grouped into six domains	Energy conservation	Mobility and transportation	Consumerism	Waste avoidance Recycling	Vicarious behaviors toward conservation
Whitmarsh and O’Neill [182]	Proenvironmental behavior	Energy and water use	Transport actions	Environmentally sound shopping choices	Waste behavior
Swim and Becker [196]	Environmentally friendly behavior	Energy conservation		Change in food consumption		Activism for climate change
Lanzini and Thøgersen [197]	Self-reported proenvironmental behaviors	Energy and water conservation	Public transport Biking Carpooling	Green purchasing	Recycling Saving paper	Volunteering
López-Mosquera et al. [198]	Habitual proenvironmental behaviors		Reduced car use frequency	Environmentally responsible purchase frequency	Recycling frequency
Rhead et al. [199]	Proenvironmental behavior categories	Water and energy conservation	Travel	Food	Recycling
Larson et al. [38]	Frequently studied universal actions of environmentalism and civic engagement	Water conservation Energy conservation	Environmentally conscious transportation	Green or ecofriendly purchasing	Recycling Waste reduction	Proenvironmental actions in the socio-political arena
Balundė et al. [200]	General ecological behavior	Fuel-efficient driving	Sustainable transportation modes		Recycling behavior	Environmental activism
Li et al. [53]	Review article; no single scale but categories	Energy consumption	Transport use	Purchase of green products	Recycling Waste management
Yuriev et al. [201]	Review article; no single scale but categories	Energy-saving	Traveling and commuting		Recycling	General green behaviors Other
Foster et al. [52]	Proenvironmental behavior categories	Air-conditioning Printing Drinking (to capture energy and water conservation) Computer use Light use		Sustainable shopping	Recycling

Table 2. Measurements and scale reliabilities.

Construct		α	KMO	MSA
	Item
Ascription of environmental responsibility (AER)		0.73	0.71
	I feel jointly responsible for environmental pollution, losses of biodiversity, and global warming because of …
	… my consumption of resources (e.g., energy and water). (AER_01)			0.68
	… my mobility behavior. (AER_02)			0.74
	… my food consumption (e.g., meat consumption). (AER_03)			0.77
	… the waste I generate. (AER_04)			0.69
Proenvironmental work climate (PEWC)		0.92	0.89
	Our organization believes it is important to protect the environment. (PEWC_01)			0.91
	The goals of our organization are directly aligned with environmental issues and concerns. (PEWC_02)			0.91
	In our organization, employees try to minimize harm to the environment. (PEWC_03)			0.89
	In our organization, employees care about the environment. (PEWC_04)			0.91
	Our organization’s environmental efforts receive full support from our senior management. (PEWC_05)			0.87
	Our organization’s environmental goals are driven by the senior management team. (PEWC_06)			0.87
Affective organizational commitment (AC)		0.88	0.71
	Working for my organization has a great deal of personal meaning to me. (AC_01)			0.78
	I feel a strong sense of belonging to my organization. (AC_02)			0.65
	I feel emotionally attached to my organization. (AC_03)			0.72
Personal proenvironmental norms (PEN)		0.78	0.76
	I feel a personal obligation to …
	… fulfill my tasks at the workplace as resource-conserving as possible (e.g., saving energy and water). (PEN_01)			0.73
	… be mobile as environmentally friendly as possible during my work (e.g., travel to work, business travels, short distances). (PEN_02)			0.76
	… to buy or consume environmentally friendly produce at the workplace (e.g., seasonal produce, locally grown, and organic foods). (PEN_03)			0.79
	… produce as little waste as possible at my workplace, and recycle paper, beverage bottles, etc. (PEN_04)			0.76
Voluntary proenvironmental behavior (VPBE)		0.81	0.79
	I take every opportunity to actively participate in environmental protection at work. (VPBE_01)			0.82
	I do more for the environment at work than I am expected to. (VPBE_02)			0.75
	I try to convince my colleagues of the importance of protecting the environment. (VPBE_03)			0.79
	I make suggestions about environmentally friendly practices to my supervisors, in an effort to increase my company’s environmental performance. (VPBE_04)			0.82
	I point out to my colleagues their non-ecological behavior. (VPBE_05)			0.77

Notes. KMO = Kaiser–Meyer–Olkin criterion; MSA = measure of sampling adequacy.

Table 2. Measurements and scale reliabilities.

Construct		α	KMO	MSA
	Item
Ascription of environmental responsibility (AER)		0.73	0.71
	I feel jointly responsible for environmental pollution, losses of biodiversity, and global warming because of …
	… my consumption of resources (e.g., energy and water). (AER_01)			0.68
	… my mobility behavior. (AER_02)			0.74
	… my food consumption (e.g., meat consumption). (AER_03)			0.77
	… the waste I generate. (AER_04)			0.69
Proenvironmental work climate (PEWC)		0.92	0.89
	Our organization believes it is important to protect the environment. (PEWC_01)			0.91
	The goals of our organization are directly aligned with environmental issues and concerns. (PEWC_02)			0.91
	In our organization, employees try to minimize harm to the environment. (PEWC_03)			0.89
	In our organization, employees care about the environment. (PEWC_04)			0.91
	Our organization’s environmental efforts receive full support from our senior management. (PEWC_05)			0.87
	Our organization’s environmental goals are driven by the senior management team. (PEWC_06)			0.87
Affective organizational commitment (AC)		0.88	0.71
	Working for my organization has a great deal of personal meaning to me. (AC_01)			0.78
	I feel a strong sense of belonging to my organization. (AC_02)			0.65
	I feel emotionally attached to my organization. (AC_03)			0.72
Personal proenvironmental norms (PEN)		0.78	0.76
	I feel a personal obligation to …
	… fulfill my tasks at the workplace as resource-conserving as possible (e.g., saving energy and water). (PEN_01)			0.73
	… be mobile as environmentally friendly as possible during my work (e.g., travel to work, business travels, short distances). (PEN_02)			0.76
	… to buy or consume environmentally friendly produce at the workplace (e.g., seasonal produce, locally grown, and organic foods). (PEN_03)			0.79
	… produce as little waste as possible at my workplace, and recycle paper, beverage bottles, etc. (PEN_04)			0.76
Voluntary proenvironmental behavior (VPBE)		0.81	0.79
	I take every opportunity to actively participate in environmental protection at work. (VPBE_01)			0.82
	I do more for the environment at work than I am expected to. (VPBE_02)			0.75
	I try to convince my colleagues of the importance of protecting the environment. (VPBE_03)			0.79
	I make suggestions about environmentally friendly practices to my supervisors, in an effort to increase my company’s environmental performance. (VPBE_04)			0.82
	I point out to my colleagues their non-ecological behavior. (VPBE_05)			0.77

Notes. KMO = Kaiser–Meyer–Olkin criterion; MSA = measure of sampling adequacy.

A Kaiser–Meyer–Olkin (KMO) value above 0.6 [202], the rejection of the Bartlett test [203], and indicator-specific measures of sampling adequacy (MSA) of above 0.5 [202] indicate the suitability of all measurement indicators. Additionally, confirmatory factor analyses (see Appendix A) yielded good fit statistics for the constructs of the hypothesized VPBE model (CMIN/DF ratio = 1.66, RMSEA = 0.059, CFI = 0.930, and SRMR = 0.054) [204,205,206,207,208]. In sum, meeting reliability and validity criteria on different levels (that is, the measurement and the construct level) allowed for further tests on the hypothesized relationships.

4. Results

The descriptive statistics and correlations shown in Table 3 provide the first insights into the relationships between the tested constructs. The results of the moderated mediation are summarized in Table 4. All regression models are statistically significant with reasonable R² values.

Table 3. Descriptive statistics and Pearson correlations.

No.	Measure	Mean	SD	1	2	3	4	5	6	7	8
1	AER	3.26	0.80	—
2	PEWC	3.15	0.93	0.06	—
3	AC	3.24	0.90	0.16 **	0.25 **	—
4	PEN	3.69	0.70	0.29 **	0.15 *	0.08	—
5	VPBE	2.57	0.78	0.19 **	0.21 **	0.14	0.48 **	—
6	Age	24.12	2.42	–0.00	0.12	0.14	–0.01	0.12	—
7	Sex (1 = female)	0.69	0.46	0.01	–0.05	0.03	0.25 **	–0.08	–0.21 **	—
8	Graduate (1 = master)	0.65	0.48	–0.04	0.11	0.18 *	–0.05	–0.04	0.48 **	0.04	—

Notes. N = 189; Pearson correlations are presented below the diagonal. ** p < 0.01; * p < 0.05.

Table 3. Descriptive statistics and Pearson correlations.

No.	Measure	Mean	SD	1	2	3	4	5	6	7	8
1	AER	3.26	0.80	—
2	PEWC	3.15	0.93	0.06	—
3	AC	3.24	0.90	0.16 **	0.25 **	—
4	PEN	3.69	0.70	0.29 **	0.15 *	0.08	—
5	VPBE	2.57	0.78	0.19 **	0.21 **	0.14	0.48 **	—
6	Age	24.12	2.42	–0.00	0.12	0.14	–0.01	0.12	—
7	Sex (1 = female)	0.69	0.46	0.01	–0.05	0.03	0.25 **	–0.08	–0.21 **	—
8	Graduate (1 = master)	0.65	0.48	–0.04	0.11	0.18 *	–0.05	–0.04	0.48 **	0.04	—

Notes. N = 189; Pearson correlations are presented below the diagonal. ** p < 0.01; * p < 0.05.

I found empirical evidence for all tested direct effects, Hypotheses H1 through H3. In support of the norm activation theory, the results show that an employee’s individual ascription of environmental responsibility (b = 0.21; SE = 0.05; p < 0.001) serves as a suitable determinant of his or her proenvironmental norms at work. Moreover, such norms are also affected by employees’ perceptions of a proenvironmental work climate (b = 0.10; SE = 0.05; p < 0.05). Thus, Hypotheses H2 and H3 are supported. Proenvironmental norms, in turn, serve as a direct predictor of VPBE (b = 0.49; SE = 0.07; p < 0.001), supporting Hypothesis H1.

I further examined whether affective organizational commitment conditions the activation of proenvironmental norms at work (cf., Hypotheses H4 and H5). To avoid issues of multicollinearity and to allow for better interpretability of the results, I mean-centered independent and moderating variables before the analysis [209,210].

Table 4. Results of the regression analyses.

		Model 1
Dependent variable: Personal proenvironmental norms		Estimate	SE		t	p		LLCI	ULCI
	Constant	3.66	0.05		73.38	0.00		3.56	3.76
Independent variables
	Proenvironmental work climate	0.10	0.05		1.97	0.05		0.00	0.19
	Ascription of responsibility	0.21	0.05		4.09	0.00		0.11	0.30
Moderator
	Affective organizational commitment	0.01	0.05		0.23	0.82		–0.09	0.11
Interactions
	Affective organizational commitment x Proenvironmental work climate	0.12	0.04		2.78	0.01		0.03	0.21
	Affective organizational commitment x Ascription of responsibility	–0.03	0.05		–0.49	0.62		–0.13	0.08
R2		0.14
F(5,183)		6.04 ***
		Model 2
Dependent variable: Voluntary proenvironmental behavior of employees		Estimate	SE		t	p		LLCI	ULCI
	Constant	0.77	0.28		2.77	0.01		0.22	1.32
Independent variables
	Proenvironmental work climate	0.10	0.05		2.10	0.04		0.01	0.20
	Ascription of responsibility	0.04	0.05		0.76	0.45		–0.06	0.14
Mediator
	Personal proenvironmental norms	0.49	0.07		6.57	0.00		0.34	0.63
R2		0.25
F(3,185)		20.41 ***

Notes. *** p < 0.001. LLCI = lower limit confidence interval; ULCI = upper limit confidence interval. Antecedent variables of PEN (i.e., PEWC, AER, and AC) were mean-centered before running the regression analysis. Parameters for the moderated mediation were calculated by ordinary least squares path analysis using a customized model of Hayes [210]’s PROCESS macro for SPSS.

Table 4. Results of the regression analyses.

		Model 1
Dependent variable: Personal proenvironmental norms		Estimate	SE		t	p		LLCI	ULCI
	Constant	3.66	0.05		73.38	0.00		3.56	3.76
Independent variables
	Proenvironmental work climate	0.10	0.05		1.97	0.05		0.00	0.19
	Ascription of responsibility	0.21	0.05		4.09	0.00		0.11	0.30
Moderator
	Affective organizational commitment	0.01	0.05		0.23	0.82		–0.09	0.11
Interactions
	Affective organizational commitment x Proenvironmental work climate	0.12	0.04		2.78	0.01		0.03	0.21
	Affective organizational commitment x Ascription of responsibility	–0.03	0.05		–0.49	0.62		–0.13	0.08
R2		0.14
F(5,183)		6.04 ***
		Model 2
Dependent variable: Voluntary proenvironmental behavior of employees		Estimate	SE		t	p		LLCI	ULCI
	Constant	0.77	0.28		2.77	0.01		0.22	1.32
Independent variables
	Proenvironmental work climate	0.10	0.05		2.10	0.04		0.01	0.20
	Ascription of responsibility	0.04	0.05		0.76	0.45		–0.06	0.14
Mediator
	Personal proenvironmental norms	0.49	0.07		6.57	0.00		0.34	0.63
R2		0.25
F(3,185)		20.41 ***

Notes. *** p < 0.001. LLCI = lower limit confidence interval; ULCI = upper limit confidence interval. Antecedent variables of PEN (i.e., PEWC, AER, and AC) were mean-centered before running the regression analysis. Parameters for the moderated mediation were calculated by ordinary least squares path analysis using a customized model of Hayes [210]’s PROCESS macro for SPSS.

According to Hypothesis H4, the effect of ascriptions of environmental responsibility on proenvironmental norms was assumed to be positively moderated by affective organizational commitment. This hypothesis must be rejected (b = −0.03, SE = 0.05; p ≥ 0.05). Affective organizational commitment does not strengthen norm activation in the workplace when employees already feel responsible for environmental issues. Considering Hypothesis H5, which assumed affective organizational commitment to reinforce the relationship between a proenvironmental work climate and proenvironmental norms, our results clearly indicate a positive interaction effect (b = 0.12; SE = 0.04; p < 0.05). Therefore, Hypothesis H5 is supported. As illustrated in Figure 2, the positive effect of a proenvironmental work climate on proenvironmental norms increases when employees experience higher levels of affective organizational commitment.

5. Discussion

5.1. Normative Mechanisms Underlying VPBE: Distinguishing Integrated and Introjected Proenvironmental Norms

One objective of the study was to broaden the knowledge of intrapersonal normative processes of VPBE by testing for interdependencies between relevant determinants, such as employees’ ascription of environmental responsibility, their perceptions of a proenvironmental work climate, and their affective organizational commitment. The findings demonstrate that proenvironmental norms at the workplace are activated by intrapersonal considerations of employees’ own responsibility for the environment and their evaluation of the proenvironmental climate within an organization. Hence, the study shows that employees’ internal motivation is indeed a key mechanism to explaining proenvironmental behavior at the workplace; a finding that is, for instance, in accordance with Graves and Sarkis [211]’s findings on proenvironmental behavior of Chinese and Faraz et al. [147]’s insights on Pakistani employees.

Personal proenvironmental norms mediate both perceptions and ascriptions of environmental responsibility in relation to VPBE. In addition, the results show that there is a conditional effect between a supportive proenvironmental work climate and employees’ affective organizational commitment, which reinforces the development of proenvironmental norms at work. In that regard, the applied normative lens points to different forms of internalized motivations [31,212] that affect VPBE. Other than expected, the empirical data support only one of the two hypothesized interaction effects. While affective organizational commitment acts as a catalyst for the emergence of employees’ proenvironmental norms when employees perceive the proenvironmental work climate as advantageous, the very same commitment fails to reinforce proenvironmental norms that are activated by employees’ intrapersonal ascriptions of environmental responsibility. In the following, I argue that both results, however, can be explained by drawing on Thøgersen [31]’s norm taxonomy and the distinction of personal proenvironmental norms as either being integrated or introjected.

On the one hand, the lack of a significant correlation between affective commitment and proenvironmental norms (r = 0.08; p ≥ 0.05) indicates that an employee’s thoroughly integrated—in other words, fully internalized—motivation to behave pro-environmentally outweighs considerations of organizational desirability and connectedness. That is, employees who are driven by their attachment to nature and their inner sense of responsibility cannot be motivated to perform VPBE by means of organizational efforts that target such employees’ affective commitment toward the organization.

On the other hand, affective commitment positively moderates the relationship between a proenvironmental work climate and proenvironmental norms at the workplace. In line with previous empirical research (e.g., [22]), the results suggest that a supportive proenvironmental work climate initiates a feeling of moral obligation to practice VPBE for the organization. This moral obligation is reinforced by employees’ emotional attachment to their organization and not the natural environment. As such, the drive to perform VPBE points to a rather introjected, i.e., superficially internalized, motivational root of VPBE. That is, under conditions of an emphasized proenvironmental work climate, employees with a strong affective commitment can be motivated to perform VPBE even if they do not care about the environment themselves. In such cases, VPBE would then be performed because employees know that it is an extra-role behavior that is expected from them, and they would comply with that expectation to benefit the organization they strongly feel associated with. This finding somehow corresponds with Raza et al. [14]’s study that found organizational pride to trigger VPBE by building on employees’ desire to reciprocate. Hence, addressing introjected motives constitutes a promising, non-environmentally centered path for managers and organizations to subtly encourage proenvironmental behavior in the workplace.

5.2. Theoretical Implications for the Application of the Norm Activation Model to the Corporate Context for Proenvironmental Behavior

A further objective of the study was to clarify associations among key variables of the norm activation model and to show how the model can be adapted to fit the corporate context for VPBE. The results suggest that the norm activation model—expanded by organizational determinants from research on OCBE—cannot merely be transferred to the organizational context, but rather it also serves as a promising theoretical underpinning for the investigation of VPBE. This constitutes an important contribution to a better understanding of VPBE, because although several studies have previously shown that voluntary and discretionary behaviors tend to be strongly influenced by personal inclinations (cf., [213,214] for volunteer work and [215] for organizational citizenship behavior), only recently have studies started to investigate personal norms against the backdrop of VPBE (e.g., [216]), and a coherent framework is still missing. Considering the potential of integrating multiple theories to advance knowledge on antecedents of proenvironmental behaviors (e.g., [217]), the approach of enriching norm activation theory by insights gained from OCBE literature can serve as a starting point for further in-depth analysis of employees’ moral motives to engage in VPBE.

5.3. Implications for Practice

Even though encouraging proenvironmental behavior constitutes an urgent global challenge [218], the present study supports Hahn and Ostertag [163]’s view that organizations cannot easily foster VPBE. Personal norms can be influenced only in the long run as they are learned from shared expectations in social interactions. However, the present results show that an appropriate organizational climate, which considers the meanings that employees attach to their experiences at work [122], might be a possible starting point.

Although research on organizational climate has long recognized the influence of perceived organizational support on employees’ organizational citizenship behaviors [128,219,220], the present study shows that this influence also holds for an organizational climate directed toward the environment and VPBE. The findings suggest that a proenvironmental work climate plays a crucial role in activating proenvironmental norms of employees. Keeping in mind that VPBE can barely be supported by formal programs or controlled by formal incentive schemes [3,35], organizations might focus on the salience of a proenvironmental work climate as a means to encourage VPBE [117,221]. That is, other than VPBE, a proenvironmental work climate can be controlled by organizations [25,222], for instance, through green HRM practices [10,223] and by providing employees with the necessary tools for ethical behavior [224]. Aside from communicating encouraging messages for desired behaviors and discouraging messages for undesired ones (e.g., [225]) or recruiting employees with a strong moral compass that are more likely to behave ethically (e.g., [226]), measures such as sharing best practices for VPBE, establishing environmental goals and disseminating them throughout the organization, or publishing environmental performance statistics might come to the fore to cultivate proenvironmental norms that eventually translate into VPBE.

5.4. Limitations and Future Research Directions

This study has several limitations. First, the data underlying this study stem from a single source, which could constitute a source of common method bias [168]. Beyond the measures described in the methods section, I tried to minimize this bias, for instance, by questioning student workforce with different backgrounds (e.g., jobs in different industries). However, future research could seek to complement and verify the VPBE framework through external evaluations by coworkers or superiors [36,50]. This would allow scholars to test whether self-reported results are consistent with observed behavior [130].

Second, although a plethora of empirical research indicates that norms are antecedents of behavior, and ascriptions and perceptions of interpersonal as well as organizational factors might cause the activation of norms, the possibility of reverse causality cannot be ruled out entirely. However, in line with prior literature and given the fact that the study builds on insights from widely accepted theoretical foundations (e.g., norm activation theory [34] and value–belief–norm theory [114]), I agree that the ability of a longitudinal design to reflect causality tends to be overstated and would have only offered limited advantages over the applied cross-sectional design [227]. Moreover, designing a longitudinal study would have been rather difficult and risky, since the timeframe for personal norms to cause VPBE is unknown [227]. In sum, the advantages commonly associated with cross-sectional designs, such as cost-effectiveness and short data collection period (e.g., [228]), outweighed its potential disadvantages, making the cross-sectional design the method of choice for the present study.

Third, although I do not expect that a distinction between the student workforce and other employee groups (e.g., full-time or tenured employees) would threaten the validity of the proposed VPBE framework—as this is likely the case with job attribute preferences or the like that change from one employee group to another (e.g., [229])—such a possibility cannot be ruled out entirely. Specifically, except for assessing the student workforce’s affective commitment, the study participants have not been asked about their active engagement in their organization. Therefore, I encourage future research to test the VPBE model by (a) drawing on other groups of employees and (b) including further individual determinants that may impact the activation of personal proenvironmental norms at work, as the understanding of the underlying mechanisms of proenvironmental behavior, and VPBE in particular, is still in its infancy [53].

In addition, the study yields further promising avenues for empirical research. First, as discussed, the results provide an informative basis that the degree of internalization of norms might be a promising starting point for further research on normative mechanisms underlying VPBE. The distinction between integrated and introjected norms might help scholars and managers alike to better understand both, differences in VPBE between and within employees depending on the situation they are in. In that regard, for instance, incorporating different degrees of moral endorsement may further enrich our knowledge of VPBE [173].

Second, in this study, I included three components of a proenvironmental work climate: perceived organizational support for the environment, perceived colleague support for the environment, and senior management commitment to the environment. As employees encounter these three complementary types of social exchange relations with their colleagues, their superiors, and the company as a whole on a daily basis, all three points of reference should be examined more thoroughly [22]. Considering that corporate hierarchies are increasingly flattening, and thus, social exchange between colleagues is becoming more important than ever before [230,231,232], it is surprising that research on coworkers’ advocacy for the environment [233] and the general relationships between colleagues who operate at the same organizational level has only recently gained momentum [21,22,124]. Through the transfer of knowledge and experience, employees can be motivated and empowered by their colleagues to behave pro-environmentally [234,235]. Beyond, Ng and Sorensen [236]’s meta-analytical findings provide nuanced insights into the relational patterns among perceived coworkers’, supervisors’, and organizational support on various micro-level outcome variables. Therefore, future research could either try to thoroughly implement cross-level effects of organizational-level determinants [237] or disentangle the study’s aggregated conceptualization of a proenvironmental work climate to further investigate how its different features affect VPBE.

5.5. Conclusions

Organizations are increasingly pressured to operate pro-environmentally to contribute to sustainable development. Encouraging VPBE in the workplace reflects one option for meeting this challenge. Against this backdrop, this study investigated the normative antecedents of VPBE. The study contributes to the research field as it helps to understand how employees can be motivated to perform VPBE and by providing empirical evidence for the applicability and integrative capacity of norm activation theory in explaining the emergence of VPBE. To stimulate VPBE, employees’ self-ascribed environmental responsibility is as important as the perceived proenvironmental work climate. Moreover, I empirically revealed interaction effects between employees’ organizational commitment and their perceptions of a proenvironmental work climate. Consequently, the study has paved the way for further research on conditional effects between organization- and environment-related psychological determinants of VPBE. Thus, it promotes the academic understanding of VPBE and provides effective recommendations for practitioners to cultivate VPBE in organizations.