How Sustainable Corporate Social Responsibility Shapes Brand Citizenship Behavior: The Mediating Role of Brand Reliability and the Moderating Role of Corporate Social Responsibility Skepticism

1. Introduction

Along with deepening environmental concerns and shifting societal expectations, consumers now expect businesses not only to deliver economic benefits but also to align their operations with sustainable development principles [1]. Consequently, Corporate Social Responsibility (CSR) has evolved beyond mere voluntary social initiatives, emerging instead as a fundamental imperative known as sustainable CSR [2,3]. Companies today bear long-term environmental, social, and economic responsibilities. By integrating these responsibilities into the core corporate strategy, sustainable CSR has emerged as a primary driver of consumer behavior. Ultimately, sustainable CSR has fundamentally reshaped how companies position themselves to cultivate deep, value-based relationships with their stakeholders [4,5].

However, a company’s claim of engaging in sustainable CSR activities does not guarantee an automatically positive response from consumers [6,7]. As sustainability has become more prominent, consumers have become increasingly knowledgeable and critical, leading them to thoroughly question the underlying motivations behind corporate actions. According to the literature consumers’ responses to CSR initiatives largely depend on whether these activities are perceived as sincere and reliable rather than as opportunistic practices such as greenwashing [8,9]. Therefore, the favorable reception of sustainability claims by consumers depends not only on the existence of these claims but also on how clear, credible, and verifiable they are perceived to be [10,11].

When a company’s sustainable CSR efforts are perceived as genuinely aimed at contributing to society, this perception can enhance corporate reliability. Conversely, when these efforts are seen as selfish or profit-driven, the expected trust fails to materialize and it may even trigger a backlash [12]. Thus, brand reliability plays a crucial role in translating sustainable corporate claims into genuine stakeholder belief [13].

Once this perception of reliability toward the company and brand is established, consumers are able to form a deeper and more meaningful bond with the business that transcends mere commercial transactions. Believing that a sustainable and reliable brand creates value for society, consumers tend to reciprocate this positive perception by demonstrating a willingness to support, defend, and voluntarily contribute to the brand [14,15].

In this context, brand citizenship behavior—defined as voluntary, discretionary, and extra-role actions such as assisting other customers, providing constructive feedback to the firm, and advocating for the brand—transforms consumers from passive buyers into active value creators. Unlike traditional in-role behaviors such as repeat purchasing, brand citizenship behavior establishes a deep and enduring bond that helps organizations navigate market uncertainties and enhances their overall competitiveness through shared sustainable values [16,17].

The literature emphasizes that effective and sustainable CSR practices play a pivotal role in fostering more favorable relationships between businesses and their stakeholders [18,19]. Prior studies consistently link positive perceptions of sustainable CSR to enhanced corporate reputation, brand trust, and consumer-company identification. Recent research demonstrates that sustainable CSR initiatives directly influence citizenship-type behaviors when consumers perceive a company to be authentically responsible, they feel a psychological sense of belonging that motivates them to act as "good soldiers" for the brand [20,21].

Existing studies have mostly examined the impact of general CSR on loyalty or the direct effect of environmental CSR on consumer trust in isolation. However, brand reliability, brand citizenship behavior, and CSR skepticism have rarely been integrated into a single, cohesive theoretical model. As a result, the precise role of brand reliability in translating sustainable CSR into brand citizenship behavior remains unclear. Furthermore, how consumer skepticism undermines this translation process has yet to be fully elucidated in the literature [21,22].

While existing literature has extensively examined the direct effects of CSR initiatives on traditional consumer attitudes like satisfaction and loyalty the underlying mechanisms that drive consumers toward voluntary, extra-role actions, such as brand citizenship behavior and how consumer skepticism disrupts this process remain insufficiently understood. To address this gap this study propose and empirically test a moderated mediation model. The main objective of this study is to investigate the complex relationships among sustainable CSR, brand reliability, brand citizenship behavior and CSR skepticism.

This research argues that sustainable CSR shapes brand citizenship behavior primarily by building brand reliability rather than directly triggering consumer action. Because today’s consumers actively scrutinize corporate motives and remain highly alert to greenwashing. The proposed model conceptualizes CSR skepticism as a key moderator. Specifically we investigate how elevated skepticism undermines both the direct benefits of sustainable CSR and the indirect transmission pathway operating through reliability. Mapping these underlying mechanisms addresses a significant gap in the current branding and sustainability literature revealing exactly when, how and for which consumer segments CSR initiatives succeed in fostering deep, discretionary customer–brand ties. Ultimately the findings highlight that sustainable CSR goes beyond merely improving customer relationships; it is essential for driving stakeholder-oriented, accountable business practices consistent with global sustainable development goals [23,24].

2. Theoretical Background and Hypothesis Development

The conceptual framework and the relationships among the variables in this study are grounded in three complementary theoretical perspectives: Social Identity Theory, Social Exchange Theory, and Attribution Theory. By examining the impact of sustainable corporate social responsibility (CSR) initiatives on brand citizenship behaviour, this model employs these three theoretical lenses to explain how consumers interpret brands’ efforts to create societal value, how these perceptions translate into trust, and under which conditions this mechanism may weaken.

Social Identity Theory, which serves as the foundation of our model, provides the psychological underpinning for consumers' voluntary, extra-role behaviors in favor of a brand such as recommending the company, providing positive feedback and exhibiting tolerance toward service failures [25]. According to this theory, individuals have a natural tendency to identify with and integrate themselves into organizations that align with their personal values and project a positive societal image [26]. When a brand generates tangible social benefits through sustainable CSR practices and establishes a credible, ethical profile (i.e., brand reliability), consumers are likely to categorize this brand as part of their own 'in-group' [17]. By strongly identifying with these socially responsible and value-congruent brands, consumers internalize the brand's objectives and successes. Consequently, they display a natural predisposition to develop brand citizenship behaviors to actively support and advocate for the brand.

The primary driver transforming this identification into active support is the principle of reciprocity, the core of Social Exchange Theory, which serves as the second theoretical foundation of the proposed model [27]. Relationship marketing research fundamentally views the consumer-brand connection not as a simple economic transaction but as a dynamic social exchange rooted in trust and mutual benefit [28]. When a brand demonstrates a genuine commitment to environmental and social wellbeing through sustainable CSR it triggers a psychological response: consumers feel a normative obligation to reciprocate both the firms benevolence and its proven reliability [14,20]. Viewed through the lens of social exchange theory this reciprocity explains the precise mechanism by which CSR-driven brand reliability translate into citizenship behavior, ultimately inspiring customers to voluntarily invest their own time and effort into supporting the brand.

Attribution Theory serves as the final theoretical anchor for this research, illustrating that consumer responses to CSR investments are neither automatic nor guaranteed [29]. As recent literature highlights, today's consumers evaluate corporate social claims through a highly critical lens [29]. Within our proposed framework this theory elucidates the mechanics of CSR skepticism by arguing that individuals do not take sustainability initiatives at face value instead, they actively interrogate the actual motives driving corporate behavior [12]. If a brand's efforts are perceived as authentic and genuinely public-serving, the social exchange flourishes. On the other hand, suspecting a firm of opportunistic greenwashing or purely profit-driven intentions triggers intense skepticism [8]. In essence this skepticism operates as a restrictive moderating variable that actively neutralizes the capacity of sustainable CSR to establish brand reliability, thereby severely suppressing consumers' inclination to exhibit citizenship behaviors [21].

2.1. Sustainable CSR, Brand Citizenship, and Brand Reliability

Extant literature recognizes that sustainable CSR has evolved well beyond traditional corporate philanthropy, emerging instead as a strategic mechanism to cultivate enduring consumer ties and sustain competitive advantage [4,30]. Driven by a heightened awareness of socio-environmental crises, modern consumers no longer accept basic economic utility as the sole indicator of corporate performance; they actively demand strict adherence to ethical and sustainable standards [31,32]. When companies demonstrate genuine sensitivity to these societal challenges they resonate deeply with consumers' personal values, fostering a strong psychological attachment and a profound sense of belonging [26]. Empowered by this robust relational bond, customers willingly step outside their traditional roles to perform discretionary actions, such as defending the brand, guiding fellow buyers, and offering constructive insights [20,33]. Based on this theoretical rationale, we formulate the following hypothesis:

H1: Perceived sustainable CSR is positively associated with brand citizenship behaviour.

Sustainable CSR does far more than just stimulate immediate consumer responses; it fundamentally anchors brand reliability. Particularly in environments fraught with information asymmetry and market uncertainty buyers view a company’s concrete social investments as vital extrinsic signals reflecting its broader integrity, consistency, and expertise [13,34]. Viewed through the lens of attribution theory, consumers actively decode the motives behind these initiatives rather than accepting them at face value. When they evaluate a firm's social commitments to be authentic and strictly driven by a desire to benefit the community this positive appraisal naturally elevates corporate reputation, brand credibility and consumer trust [18,31]. Ultimately organizations that faithfully honor their sustainability pledges cement a unique cognitive position; they are recognized not merely as benevolent actors but as highly dependable brands capable of delivering on their promises regardless of the circumstances [19,36]. Based on this conceptual rationale, we propose the following hypothesis:

H2: Perceived sustainable CSR is positively associated with brand reliability.

When consumers develop genuine trust in a brands competence and intentions thet tend to form a deep emotional attachment, ofren categorizing the business as an extension of their own social identity or an in-group. Motivated by this psyological bond individuals willingly support the brands market sucess through voluntary advocacy seeking to reciprocate the broader societal value the firm generates [14,37]. Consequently extra-role actions, such as recommending the brand to peers, showing greater tolerance during service failures and actively defending the corporate reputation, serve as direct manifestations of established reliability and social exchange [17,38]. Drawing upon these theoretical linkages, we postulate the following hypothesis:

H3: Brand reliability is positively associated with brand citizenship behaviour.

2.2. The Mediating Role of Brand Reliability

Today's consumers do not simply take corporate social activities or initiatives at face value; rather, they actively question the underlying intentions and corporate motives behind these actions [6,12]. When sustainable CSR efforts are attributed to sincere, moral, and public-serving motives rather than being perceived as mere window-dressing or profit-maximizing tactics, consumers' evaluations of the brand become significantly more favorable [22,39]. This authentic commitment to environmental and social issues serves as a powerful indicator of the firm's overall integrity and its capacity to fulfill its commitments, thereby directly enhancing brand reliability [13,34]. In other words, sustainable CSR primarily generates a perception of brand reliability by building the brand's moral capital [18].

The translation of this established brand reliability into consumer action—namely, Brand Citizenship Behavior—is rooted in Social Exchange Theory, which forms the foundation of relationship marketing [40]. According to this theory, in market conditions characterized by information asymmetry and high uncertainty, perceived reliability mitigates the perceived risk between the consumer and the brand, ultimately deepening relationship quality [15]. Consumers are reluctant to leave the actions of a brand unreciprocated when they have no doubts about its integrity and believe it creates sustainable value for society. Driven by the principle of reciprocity inherent in social exchange, the benevolent investments of a reliable brand generate an intrinsic desire among consumers to reward the firm [14]. Spurred by this desire, consumers move beyond mere commercial transactions to exhibit voluntary, extra-role citizenship behaviors, such as defending the brand, recommending it to others, demonstrating tolerance for service failures, and providing constructive feedback [38,41].

Consequently, current literature confirms that rather than translating directly into behavior, sustainable CSR perceptions rely heavily on a psychological contract that operates through perceived reliability [31]. Sustainable CSR can effectively elicit brand citizenship behaviors only when it is transformed into brand reliability through consumers' attributions of sincerity, and when this reliability, in turn, triggers a sense of reciprocity. Building on these robust theoretical foundations, the following mediation hypothesis is proposed:

H4: Brand reliability mediates the relationship between perceived sustainable CSR and brand citizenship behaviour.

2.3. CSR Skepticism as a Moderator

Consumers do not automatically embrace sustainable Corporate Social Responsibility (CSR) initiatives favorably; rather, they actively question and attempt to make sense of the underlying motives driving corporate actions [6,12]. When consumers suspect that a firm's CSR activities lack genuine sincerity and public-serving intent—viewing them instead as driven by strategic or profit-maximizing reasons—they may develop doubt and distrust toward the company's social responsibility claims. This doubtful disposition is defined as CSR skepticism [22,42].

Primarily, this skepticism attenuates the positive relationship between sustainable CSR and Brand Citizenship by acting as a negative moderator. An authentically perceived CSR communication encourages consumers to identify with the brand and engage in voluntary, extra-role actions, such as providing constructive feedback to the firm, advocating for the brand, and assisting other customers [21,31]. However, when skeptical consumers suspect that a company is exploiting social or environmental issues merely for superficial gains or image enhancement, the ensuing psychological discomfort and perceived lack of authenticity suppress their desire to act as voluntary advocates or "good soldiers" for the brand [43]. Consequently, as the level of skepticism in the consumer's mind rises, the potential of sustainable CSR to elicit discretionary and supportive citizenship behaviors toward the brand significantly diminishes:

H5: CSR skepticism negatively moderates the relationship between perceived sustainable CSR and brand citizenship behaviour, such that the positive association weakens as CSR skepticism increases.

Similarly, CSR skepticism acts as a moderating variable that disrupts the translation of sustainable CSR into brand reliability. Brand reliability is fundamentally rooted in the consumer's belief in the company's sincerity, consistency, and capability to fulfill its promises [13]. However, when skepticism is high, consumers are less likely to view corporate social initiatives as a sign of credible moral commitment; instead, they evaluate these actions as a mere reaction to external stakeholder pressures, an instance of corporate hypocrisy, or an opportunistic greenwashing strategy [8,39]. Such profound doubt regarding the company's intentions and integrity dilutes the positive messages intended by CSR campaigns and severely hinders the firm's ability to build a reliable reputation [42]. Consequently, a high level of skepticism impedes the ability of sustainable CSR efforts to generate consumer trust, ultimately preventing the brand from being perceived as highly credible.

H6: CSR skepticism negatively moderates the relationship between perceived sustainable CSR and brand reliability, such that the positive association weakens as CSR skepticism increases.

2.4. The Moderated Mediation Effect of CSR Skepticism

The conceptual model of this study posits that rather than directly influencing Brand Citizenship, sustainable CSR initiatives primarily promote it indirectly by building Brand Reliability. However, the strength of this value transfer mechanism is not uniform across all consumers and varies depending on their level of CSR Skepticism [21]. From an Attribution Theory perspective, instead of passively accepting corporate sustainability messages, consumers actively question the underlying motives behind these actions [12]. When consumer skepticism is high, individuals are more inclined to evaluate these social initiatives as self-serving corporate endeavors rather than genuine efforts to benefit society [42,43]. This negative attribution process leads CSR campaigns to be interpreted as manipulative greenwashing tactics, effectively undermining the capacity of sustainable CSR to generate brand reliability [8,39]. Once brand reliability is compromised, consumers become more reluctant to support the brand, advocate for it, or offer constructive feedback, which in turn weakens the indirect effect of sustainable CSR on brand citizenship behavior [14,17]. Conversely, when skepticism is low, CSR efforts are perceived as more sincere. This perception helps the brand appear more credible and fosters stronger brand citizenship behavior. Consequently, the indirect effect of sustainable CSR on brand citizenship behavior via brand reliability is conditional on the consumers' level of skepticism:

H7: CSR skepticism negatively moderates the indirect effect of perceived sustainable CSR on brand citizenship behaviour through brand reliability, such that the indirect effect is weaker at higher levels of CSR skepticism.

The proposed research model is illustrated in Figure 1.

3. Materials and Methods

The present study was conducted with consumers capable of evaluating the sustainable corporate social responsibility (CSR) practices of brands. Accordingly, participants were asked to identify a brand whose social responsibility and sustainability initiatives they were familiar with, and to respond to the survey questions with that specific brand in mind. Research data were collected between March 16 and March 30, 2026, using an online questionnaire administered via Google Forms.

The survey consist of two main sections. The first section included questions designed to determine the demographic characteristics of the participants, whereas the second section contained items measuring the focal constructs: sustainable CSR, brand reliability, brand citizenship behavior, and CSR skepticism. Employing an online data collection method enabled participants to complete the survey at their own convenience and in their preferred environments, thereby ensuring a highly efficient data-gathering process.

After completing data collection phase, responses were obtained from a total of 417 participants. However, 32 questionnaires were excluded from the dataset because they were deemed incomplete, inconsistent, or carelessly filled out. Consequently, a final sample of 385 valid surveys was retained for the analyses. The fact that the sample encompasses diverse demographic groups in terms of gender, age, education and income level enables the research to reflect a broad spectrum of consumer profiles. Detailed demographic information regarding the respondents is presented in Table 1.

3.1. Measurement Instruments

We operationalized the models constructs by drawing on well-established, validated scales from prior researches. The survey instrument consisted of 16 items in total and all evaluated on a 5-point Likert scale (1 = strongly disagree, 5 = strongly agree). To capture sustainable corporate social responsibility, we adapted four items from Khan and Fatma (2023). CSR skepticism was assessed using Skarmeas and Leonidou's (2013) four-item scale. We measured brand reliability through four items modified from Bruhn, Schoenmüller, Schäfer and Heinrich (2012) while brand citizenship behavior was evaluated using four items based on the work of Helm, Renk and Mishra (2016). Before administering the final survey, we ran a pilot study to verify the clarity of the questions. Since the original instruments required translation into Turkish, we followed a rigorous review process to preserve their semantic equivalence and ensure they accurately reflected the current research context, making only minor linguistic adjustments based on the pilot feedback [22,31,44,45].

3.2. Participant Profil

An analysis of the demographic characteristics of the 385 respondents reveals that females constitute the majority of the sample (64.9%) while males account for the remaining 35.1%. Regarding age distribution, the largest segment falls within the 36–45 age bracket (29.4%), followed by the 26–35 (26.8%) and 46–55 (20.8%) age groups. In terms of educational attainment, a significant majority of the participants hold a bachelor's degree (57.1%), followed by those with a master's degree (25.7%). With respect to income, the highest concentration is observed in the 50,000–99,999 TL bracket (39.2%), trailed sequentially by the 0–49,999 TL (18.7%), 100,000–149,999 TL (17.9%), and 200,000 TL or more (16.6%) income groups. Taken together, these statistics indicate that the sample captures a highly diverse consumer base across gender, age, education, and income levels.

4. Data Analysis and Results

The research data were analyzed employing partial least squares structural equation modeling (PLS-SEM) using the SmartPLS 4 software. The selection of the PLS-SEM approach is justified by several fundamental reasons. First, rather than merely confirming existing theories, the primary objective of this study is to elucidate the relationships among the constructs and contribute to theory development. In this regard, PLS-SEM emerges as a highly suitable method for theory building and exploratory analyses [46,47].

Second, the proposed research model incorporates multiple latent variables and encompasses both mediation and moderation effects. Specifically, testing a moderated mediation framework—which integrates the mediating role of brand reliability with the moderating role of CSR skepticism—considerably increases the overall complexity of the model. The PLS-SEM method demonstrates superior performance in estimating such complex models and allows for the simultaneous evaluation of multiple relationships [48,49].

Third, PLS-SEM offers a robust approach for predictive analyses, yielding highly effective results in explaining the relationships between variables, particularly in behavioral research [47]. Given this predictive capability, it was deemed the most appropriate analytical technique for the current study, which focuses heavily on consumer perceptions and behaviors. Finally, the evaluation of the PLS-SEM outcomes, including both the measurement and structural model analyses, was conducted in strict accordance with the widely accepted guidelines and threshold criteria established in the extant literatüre [46,50,51].

4.1. Assessment of the Measurement Model

The evaluation of the measurement model involved analyzing indicator reliability alongside internal consistency, convergent validity, and discriminant validity. Within the PLS-SEM literature, outer loading values are generally expected to exceed 0.708, indicating that the items adequately capture their corresponding latent constructs [46,51]. In this study, the outer loadings for all items ranged from 0.731 to 0.959. Specifically, the items for the sustainable corporate social responsibility construct yielded loadings between 0.731 and 0.911, brand citizenship items ranged from 0.817 to 0.871, brand reliability items were between 0.884 and 0.959, and CSR skepticism items varied from 0.901 to 0.919. Because every loading value comfortably exceeded the acceptable threshold, no items were deleted from the measurement model.

Internal consistency reliability was evaluated using Cronbach’s alpha, rho_A, and composite reliability metrics. In the extant literature, Cronbach's alpha and composite reliability values exceeding 0.70 are generally recognized as indicators of adequate internal consistency [46,52]. The findings reveal that all constructs successfully satisfy this criterion. Specifically, the Cronbach's alpha values were 0.879 for brand citizenship, 0.954 for brand reliability, 0.932 for CSR skepticism, and 0.858 for sustainable corporate social responsibility. Similarly, the composite reliability values for these constructs were 0.914, 0.967, 0.951, and 0.905, respectively. These results confirm that the measurement scales employed in this research demonstrate a high degree of reliability.

Convergent validity was assessed by examining the average variance extracted (AVE) values. An AVE exceeding the 0.50 threshold demonstrates that the respective items adequately capture the variance of their corresponding latent constructs, thereby establishing convergent validity [46,52]. In this study, the AVE values emerged as 0.728 for brand citizenship, 0.880 for brand reliability, 0.829 for CSR skepticism, and 0.704 for sustainable corporate social responsibility. Because all AVE values comfortably surpass the 0.50 benchmark, it can be concluded that the constructs within the proposed model have achieved a satisfactory level of convergent validity.

Discriminant validity was evaluated using the heterotrait-monotrait (HTMT) ratio of correlations. HTMT values below the 0.85 threshold indicate that the constructs are empirically distinct from one another [51,52,53]. As detailed in Table 3, the analysis yielded the following HTMT values: 0.684 between brand reliability and brand citizenship, 0.315 between CSR skepticism and brand citizenship, 0.334 between CSR skepticism and brand reliability, 0.686 between sustainable corporate social responsibility and brand citizenship, 0.686 between sustainable corporate social responsibility and brand reliability, and 0.495 between sustainable corporate social responsibility and CSR skepticism. Since all HTMT values remain well below the 0.85 benchmark, discriminant validity is successfully established for the measurement model. To further corroborate this finding, bias-corrected and accelerated (BCa) confidence intervals derived from a 10,000-resample bootstrapping procedure were also examined. The fact that the upper bound of the 95% confidence interval does not exceed the 0.85 threshold for any construct pair confirms the empirical distinctness of the variables, thereby finalizing the establishment of discriminant validity [52,53].

The risk of common method bias and collinearity was assessed through variance inflation factor (VIF) metrics, utilizing the full collinearity assessment approach. According to Kock and Lynn, VIF values below 3.3 indicate that common method bias does not pose a severe problem. In the present study, full collinearity VIF values at the structural model level range from 1.005 to 1.877, as shown in Table 2. Consequently, it can be concluded that the model is free from critical collinearity issues and that common method bias does not threaten the validity of the research findings [54].

Table 3. Heterotrait-Monotrait (HTMT) ratio correlation.

Table 3. Heterotrait-Monotrait (HTMT) ratio correlation.

4.2. Assessment of the Structural Model

The results of the structural model analysis are depicted in Figure 2 and Table 4. To test the proposed hypotheses, a bootstrapping procedure utilizing 10,000 resamples was employed [48]. The findings reveal that sustainable corporate social responsibility (SCSR) exerts a positive and significant effect on brand reliability (β = 0.622, p < 0.001). Similarly, the impact of SCSR on brand citizenship is found to be positive and significant (β = 0.330, p < 0.001). Furthermore, brand reliability is shown to have a positive and significant influence on brand citizenship (β = 0.465, p < 0.001). Consequently, hypotheses H1, H2, and H3 are fully supported.

An evaluation of the model's explanatory power indicates that sustainable corporate social responsibility accounts for 41.8% of the variance in brand reliability (R² = 0.418). Moreover, the variables incorporated into the model collectively explain 52.8% of the variance in brand citizenship (R² = 0.528). Overall, these results demonstrate that the proposed model possesses a moderate level of explanatory power.

Simultaneously, the indirect effects were evaluated employing the analytical approach recommended by Nitzl et al. (2016) .The findings demonstrate that the impact of sustainable corporate social responsibility on brand citizenship is significant when mediated by brand reliability (β = 0.289, p < 0.001). Given that the indirect effect is significant and the direct effect also retains its significance, it is concluded that complementary partial mediation exists within this relationship [55]. These findings reveal that brand reliability serves as a critical underlying mechanism in the relationship between sustainable corporate social responsibility and brand citizenship. Consequently, hypothesis H4 is fully supported.

Following this, a two-stage approach was employed to investigate the conditional effect of CSR skepticism on the relationships between sustainable corporate social responsibility (SCSR) and both brand citizenship and brand reliability [56]. To achieve this, CSR Skepticism × SCSR interaction terms were introduced into the model. The findings indicate that the effect of the interaction term on brand citizenship is negative and significant (β = -0.112, p = 0.003). Taken together, these results demonstrate that at a mean level of CSR skepticism, the effect of SCSR on brand citizenship stands at 0.347. In instances of high CSR skepticism (i.e., a one standard deviation increase), the strength of this relationship decreases by the interaction coefficient, dropping to 0.235. Conversely, under conditions of low CSR skepticism (i.e., a one standard deviation decrease), the effect magnitude increases to 0.459.

Similarly, the impact of the interaction term on brand reliability was also found to be negative and significant (β = -0.166, p < 0.001). Accordingly, while the effect of SCSR on brand reliability is 0.603 at an average level of CSR skepticism, this effect retracts to 0.436 under high skepticism and climbs to 0.769 when skepticism is low. Ultimately, these findings provide compelling evidence that as CSR skepticism increases, the favorable impacts of SCSR on both brand citizenship and brand reliability weaken. Therefore, hypotheses H5 and H6 are fully supported.

The interaction plots presented in Figure 2 clearly illustrate the moderating effect of CSR skepticism on the relationships between SCSR and both brand citizenship and brand reliability. The graphs demonstrate that the impact of SCSR on brand citizenship and brand reliability is considerably stronger when CSR skepticism is low; conversely, these effects attenuate as the level of skepticism increases. In other words, consumers with low levels of CSR skepticism respond more favorably to the brand's sustainable CSR initiatives, whereas highly skeptical consumers evaluate these activities in a much more constrained manner.

These findings indicate that CSR skepticism operates as an attenuating moderator within the proposed model, meaning that the influence of sustainable CSR on consumer behavior varies contingently upon this variable.

Ultimately, consumer trust serves as the crucial mechanism that converts corporate sustainability efforts into tangible behavioral shifts. When public doubt surrounding a company's social motives intensifies, the anticipated benefits for both brand reliability and citizenship behavior rapidly deteriorate. Rather than acting solely as a direct negative antecedent. Our findings reveal that skepticism functions as a critical moderating variable that actively constrains the relational pathways within the framework. To ensure sustainable CSR investments genuinely engage the target audience, managers must therefore prioritize radical transparency, build authentic credibility, and maintain absolute alignment between their corporate claims and concrete actions.

4.3. Moderated Mediation Analysis

The baseline indirect effect of SCSR on brand citizenship behavior through brand reliability was found to be significant (β = 0.289, p < 0.001). When CSR skepticism was incorporated into the model, the conditional indirect effect slightly decreased (β = 0.261), indicating that the strength of the mediation mechanism varies depending on the level of skepticism.

We tested the proposed moderated mediation framework to understand whether CSR skepticism restricts the indirect transmission of SCSR to brand citizenship via brand reliability. Using a bootstrapping approach with 10,000 resamples the analysis confirmed a significant and and positive conditional indirect effect of SCSR on citizenship behaviors through the reliability mechanism (β = 0.261, t = 8.158, p < 0.001). Although the independent impact of the skepticism variable on this pathway was not statistically significant (β = -0.026, t = 1.323, p = 0.186), the interaction term yielded a significant negative moderated mediation index (β = -0.072, t = 3.777, p < 0.001).

These results clearly demonstrate that consumer skepticism operates as a critical moderating variable as doubts about corporate motives intensify, the indirect capacity of SCSR to foster brand citizenship through reliability is severely weakened.

The results demonstrate that when consumer skepticism toward CSR is low sustainable CSR initiatives bolster brand reliability more robustly, which subsequently drives higher levels of brand citizenship behavior. In contrast, as CSR skepticism increases, the strength of this indirect mechanism deteriorates. Ultimately CSR skepticism functions as a critical moderating variable that weakens both the direct linkages and the indirect pathways connecting sustainable CSR to brand citizenship. In light of these findings, hypothesis H7 is fully supported.

5. Discussion

This study investigated the impact of Sustainable CSR practices on brand citizenship behavior within an integrated framework, specifically examining the mediating role of brand reliability and the moderating role of CSR skepticism. The PLS-SEM findings fully support all hypotheses ranging from H1 to H7. These results demonstrate that sustainable CSR does more than merely generate positive brand outcomes, it also acts as a decisive mechanism in translating transparent, credible and verifiable sustainability communication into actual consumer support.

5.1. Theoretical Implications

Firstly, the research findings demonstrate that sustainable CSR exerts positive and significant direct effects on both brand citizenship behavior and brand reliability (H1 and H2) and that brand reliability, in turn, substantially enhances citizenship behavior (H3). These results align with prior studies emphasizing that sustainable CSR extends beyond mere legal compliance, rather it serves as a strategic investment capable of transforming customers into voluntary advocates and “good soldiers” for the firm [20,31,57]. When organizations fulfill their environmental and social responsibilities consumers tend to perceive the brand as an extension of their own self-concept, as predicted by social identity and social exchange theories [25,26]. Motivated by this reciprocal bond consumers willingly engage in extra-role behavior such as advocating for the brand showing patience during occasional service mistakes and sharing valuable feedback [17,20].

Secondly, by confirming the mediating role of brand reliability (H4) this study demonstrates that sustainable CSR is predicated on a sequential psychological contract operating through trust-building rather than directly producing a behavioral response. The analyses reveal that brand reliability functions as a partial bridge in the translation of CSR activities into brand citizenship behavior. The extant literature similarly indicates that in markets characterized by compromised trust or high information asymmetry, a firm's social responsiveness is perceived by consumers as a signal of honesty and competence [13,34]. Consequently, for customers to evolve into voluntary advocates of a brand, CSR signals must primarily fortify their belief in the brand's honesty, credibility, and reliability [19,38]. This finding is consistent with prior research emphasizing that consumers’ trust and behavioral responses to sustainability-oriented initiatives are largely shaped by the perceived sincerity and credibility of these efforts [58].

The third and perhaps most substantial theoretical contribution of this study is the empirical evidence it provides regarding the moderating role of CSR skepticism (H5, H6) and its function within the moderated mediation mechanism (H7). Drawing on attribution theory consumers are not passive recipients of corporate messages, instead they actively question and interpret the motives behind firms actions [6,12]. The findings of this study indicate that higher levels of CSR skepticism weaken the positive influence of perceived sustainable CSR on both brand reliability and brand citizenship behaviour. In particular, when consumers perceive CSR initiatives as insincere, self-serving or as attempts at “greenwashing,” the potential of these initiatives to create value is substantially reduced [8,59].

In addition, the support for H7 shows that the indirect effect of perceived sustainable CSR on brand citizenship behaviour through brand reliability becomes considerably weaker among consumers with high levels of skepticism. This result highlights how skepticism interferes with the mechanism through which brand reliability translates CSR perceptions into favourable behavioural outcomes. By demonstrating this process within a single integrated framework, the study contributes to the literature by offering a clearer understanding of how and under what conditions CSR initiatives fail to deliver their expected benefits [21,42].

5.2. Managerial Implications

These findings offer several practical implications for brand managers across different sectors. The results suggest that simply investing in CSR initiatives is not enough; what truly matters is how these efforts are perceived by consumers. In particular, CSR activities need to be seen as sincere, credible, and consistent. To reduce the negative effects of CSR skepticism (H5, H6, H7), managers should prioritize transparency when designing and communicating their CSR strategies. This involves clearly showing the alignment between what the company claims and what it actually does, in other words, ensuring a strong company–CSR fit. Previous research also highlights that the way sustainability initiatives are communicated plays a key role in shaping how consumers interpret and evaluate the credibility of CSR efforts [61].

In addition, companies should be cautious about being perceived as engaging in “greenwashing.” One way to address this risk is by supporting CSR claims with concrete evidence, such as third-party certifications and independent audit reports. Providing measurable and verifiable sustainability targets can help reduce consumers’ doubts about firms’ underlying motives and strengthen the overall credibility of CSR communication [58].

Finally, if firms aim to encourage brand citizenship behaviours—such as positive word-of-mouth or greater tolerance toward service failures—they need to adopt a long-term perspective. This means embedding sustainable CSR practices into the brand’s core value proposition and linking them with customer loyalty initiatives. Rather than treating sustainability communication as a short-term positioning tool, companies should view it as an integral part of their responsibility toward stakeholders. In doing so, they can build stronger trust, enhance accountability, and contribute more meaningfully to broader sustainability goals.

5.3. Limitations and Future Research Directions

Despite its theoretical and practical contributions this study has several limitations that open up directions for future research. First the cross-sectional design limits the ability to make strong causal interpretations or capture changes over time. Future studies could address this by using longitudinal or experimental approaches to better understand how CSR perceptions evolve and influence brand citizenship behaviour.

Secondly the research was conducted within a single-country context which may limit the generalizability of the findings. Testing the proposed model across different cultural settings and industries would provide a more comprehensive understanding of the relationships examined. In particular, applying the model to more controversial industries, such as tobacco or oil, may help clarify the conditions under which CSR is more or less effective.

Finally, future research could extend the model by incorporating additional mediating and moderating variables, such as customer and company identification, brand love, or environmental concern. Exploring these factors may offer deeper insights into the psychological processes through which sustainable CSR shapes consumer behaviour.

6. Conclusion

The main aim of this study was to better understand how sustainable corporate social responsibility (SCSR) leads to brand citizenship behaviour while considering the role of consumer skepticism. The findings support the proposed moderated mediation model and show that SCSR is more than a purely symbolic practice, it can function as a strategic tool that strengthens consumer and brand relationships.

In line with social exchange theory the results indicate that SCSR has a positive effect on both brand citizenship behaviour and brand reliability. When companies go beyond their economic responsibilities and are perceived as acting responsibly consumers are more likely to respond positively. In this regard, they may move beyond being passive buyers and become more willing to support the brand through voluntary behaviours. The findings also show that brand reliability plays an important mediating role in this process. In other words, SCSR encourages brand citizenship behaviour not only directly, but also by increasing perceptions of trust and credibility.

Another important contribution of the study is the role of CSR skepticism. Although CSR is often discussed in terms of its positive outcomes, the present findings show that these benefits become weaker when consumers question the sincerity of a company’s motives. From the perspective of Attribution Theory, consumers evaluate why firms engage in CSR activities. If these initiatives are seen as opportunistic or as a form of greenwashing, the positive effects of SCSR on both brand reliability and brand citizenship behaviour decrease. This suggests that skepticism acts as an important moderaor variable in the CSR process.

These findings also offer practical implications for managers. Simply investing in CSR activities is not enough. What matters is whether these efforts are perceived as genuine, consistent, and credible. For this reason, managers should place transparency at the centre of CSR communication and ensure a strong fit between the company and its social initiatives. Supporting CSR claims with concrete evidence, such as third-party certifications or verifiable sustainability targets, may also help reduce skepticism and improve credibility. If companies want to encourage positive consumer behaviours, they need to treat sustainability not as a short-term promotional tool, but as part of their long-term brand strategy.

Despite these contributions, the study has some limitations. Since the data are cross-sectional, causal interpretations should be made with caution. Future studies could use longitudinal or experimental designs to examine how CSR perceptions and skepticism develop over time. It would also be useful to test this model in different cultural settings and in industries where CSR claims are more likely to be questioned. In addition, future research may include other mediating or moderating variables, such as customer–company identification, brand love, or perceived service quality, to further explain how sustainable CSR shapes consumer responses.