Bridging Human Behavior and Environmental Norms: A Cross-Disciplinary Approach to Sustainable Tourism in Vietnam

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper developed and tested a comprehensive model that combines Theory of Planned Behavior (TPB) and Value Belief Norm (VBN) theory to study the sustainable consumption behavior (SCB) of domestic tourists in Vietnam. Provided an examination of how rational decision-making and normative pressure work together to promote friendly travel behavior in the context of collective ownership. This is a meaningful research field. Authors can consider the following suggestions to further improve the quality of their papers.

1. The literature review provides a literature search for the Theory of Planned Behavior (TPB) and Value Belief Norm (VBN) theories, but there is not much discussion on the connection between these two theories. It is recommended that the author establish a dedicated chapter for discussion, as this is the theoretical foundation of this article.

2. The research question should be further sorted out. The current research question 3 has little to do with this article. The research question should focus on the true contribution of this article.

3.How to stratify online questionnaires for statistical analysis. Stratified Random Sampling is a statistical sampling method that aims to improve sample representativeness and accuracy by dividing a population into different subgroups ("layers") and conducting independent random sampling from each layer. It is particularly suitable for situations where there is significant heterogeneity within the overall population. How to deal with this heterogeneity in online surveys? Authors should provide detailed explanations in the text.

4. The model includes Perceived Behavioral Control (PBC), Destination Characteristics (DES), Personal Norms (PN), Community Influence (CI), Environmental Awareness (EA), and Attitude (ATT) as predictors. Regression analysis is a supplementary analysis method. How to select independent variables? How are these independent variables considered as independent variables, and what is the theoretical basis and literature foundation?

5. The references should be updated with the latest research on the relationship between Theory of Planned Behavior (TPB) and Value Belief Norm (VBN) theory to provide readability and reliability of the article.

Author Response

Comment 1: The literature review provides a literature search for the Theory of Planned Behavior (TPB) and Value Belief Norm (VBN) theories, but there is not much discussion on the connection between these two theories. It is recommended that the author establish a dedicated chapter for discussion, as this is the theoretical foundation of this article.
Response: We greatly appreciate this suggestion, which enhances the theoretical foundation of our study. To address this, we have introduced a new subsection (2.3: “Integration of TPB and VBN,” pp. 4–5) in the Literature Review, explicitly discussing the synergy between TPB and VBN. This section articulates that “while TPB captures proximal cognitive drivers of behavior, VBN addresses distal value-based influences, together offering a comprehensive framework for understanding sustainable tourism behavior.” We further highlight the relevance of this integration in Vietnam’s collectivist context, noting that “subjective norms may amplify personal norms, as social expectations reinforce intrinsic moral obligations [13].” References to Han [11], Kiatkawsin & Han [15], and Landon et al. [18] bolster this discussion, ensuring a robust theoretical grounding.

Comment 2: The research question should be further sorted out. The current research question 3 has little to do with this article. The research question should focus on the true contribution of this article.
Response: We agree with this critical observation and have revised Research Question 3 to align with the study’s core contribution: “How do personal norms directly shape sustainable consumption behavior in Vietnam’s collectivist culture, bypassing behavioral intention, and how does this differ from traditional TPB–VBN models?” (p. 2). This reformulated question emphasizes the novel direct Personal Norms (PN) to Sustainable Consumption Behavior (SCB) pathway (H4b), which challenges Western-centric models prioritizing intention, thereby underscoring the study’s unique contribution.

Comment 3: How to stratify online questionnaires for statistical analysis? Stratified Random Sampling is a statistical sampling method that aims to improve sample representativeness and accuracy. How to deal with this heterogeneity in online surveys? Authors should provide detailed explanations in the text.
Response: Thank you for raising this important methodological concern. We have significantly expanded the description of our sampling strategy in Section 3.2 (p. 6), clarifying that “a stratified random sampling approach was employed, with strata based on national tourism profiles for region, age, and gender [4].” We further detail that “surveys were distributed through online platforms (social media and travel forums) and in-person at key tourist sites, yielding 549 valid responses from 650 distributed questionnaires (response rate: 84.5%) after excluding incomplete or inconsistent submissions.” A new table (Table X, p. 6) summarizes demographic quotas, addressing heterogeneity. We also acknowledge that “the online format may underrepresent less tech-savvy groups, suggesting the need for mixed-methods approaches in future research,” enhancing methodological transparency.

Comment 4: The model includes Perceived Behavioral Control (PBC), Destination Characteristics (DES), Personal Norms (PN), Community Influence (CI), Environmental Awareness (EA), and Attitude (ATT) as predictors. Regression analysis is a supplementary analysis method. How to select independent variables? How are these independent variables considered as independent variables, and what is the theoretical basis and literature foundation?
Response: We apologize for the oversight and have corrected “Community Influence (CI)” to “Consumer Innovativeness (CI)” throughout the manuscript for consistency with our theoretical framework. To address your query, we have added a detailed paragraph in Section 3.3 (p. 7), justifying the selection of independent variables: “TPB constructs (PBC, ATT) were adapted from Ajzen [2] and Han [11]; VBN constructs (PN, EA) from Stern et al. [35] and Kiatkawsin & Han [15]; and contextual factors (DES, 4 items; CI, 3 items) from Pulido-Fernández & López-Sánchez [31] and Pinho & Gomes [30], respectively.” Sample items (e.g., “I prefer low-impact transportation options when traveling” for SCB) illustrate operationalization. A new paragraph in Section 3.4 (p. 7) explains the theoretical and empirical basis for their inclusion in regression analysis, ensuring clarity and rigor.

Comment 5: The references should be updated with the latest research on the relationship between Theory of Planned Behavior (TPB) and Value Belief Norm (VBN) theory to provide readability and reliability of the article.
Response: We have updated the reference list with recent high-impact studies (2023–2024), including Mathur et al. (2024) on integrated TPB–VBN frameworks [23], Li et al. (2023) on sustainable tourist behavior [22], Khánh (2024) on Vietnam’s sustainable tourism [14], and Nguyen et al. (2024) on Vietnamese tourist behaviors [24–27]. These additions enhance the timeliness, reliability, and global relevance of our theoretical foundation, improving the manuscript’s accessibility and credibility.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The sustainable tourism consumption behavior model constructed in this study is theoretically innovative and has practical significance. However, optimizing some details can enhance the quality of the article:
(1)The references in the main text should be numbered in the order of their appearance, starting from 1. Currently, the numbering sequence is disordered.
(2)When the concept of sustainable tourism is first mentioned in the Introduction, it should be defined and explained to enable readers to understand its meaning more quickly.
(3)The font sizes in the text of Figure 2 are inconsistent, and one of the figures lacks the horizontal and vertical coordinate axes, which need to be supplemented and improved.
(4)The prospects for international tourists or cross-cultural comparisons should be supplemented to verify the external validity of the model.

Author Response

Comment 1: The references in the main text should be numbered in the order of their appearance, starting from 1. Currently, the numbering sequence is disordered.
Response: We appreciate your attention to this formatting issue. We have thoroughly revised the reference numbering throughout the manuscript to ensure sequential ordering based on their first appearance in the text, starting from [1], in accordance with Sustainability’s guidelines. For example, in Section 1, references are now consistently ordered (e.g., [19, 20, 27]), ensuring clarity and compliance with journal standards.

Comment 2: When the concept of sustainable tourism is first mentioned in the Introduction, it should be defined and explained to enable readers to understand its meaning more quickly.
Response: Thank you for this valuable suggestion. We have added a concise and clear definition of sustainable tourism at its first mention in the Introduction (p. 2): “Sustainable tourism—defined as travel that meets present needs without compromising the ability of future generations to meet theirs—is increasingly critical worldwide [40].” This addition provides immediate context, enhancing accessibility for readers unfamiliar with the term.

Comment 3: The font sizes in the text of Figure 2 are inconsistent, and one of the figures lacks the horizontal and vertical coordinate axes, which need to be supplemented and improved.
Response: We are grateful for your observation regarding visualization quality. We have redesigned Figure 2 (p. 8) to standardize font sizes across all elements (labels, annotations, and captions) and added horizontal and vertical coordinate axes to all charts, including bubble and scatter plots. The revised figure now ensures visual consistency and facilitates data interpretation, addressing your concerns.

Comment 4: The prospects for international tourists or cross-cultural comparisons should be supplemented to verify the external validity of the model.
Response: We concur with this insightful suggestion to strengthen the model’s external validity. In Section 5.3 (p. 14), we have expanded the discussion on cross-cultural implications, stating that “future studies could test the model in other collectivist cultures, such as Thailand or Indonesia, to evaluate its cross-cultural applicability.” We also acknowledge potential differences between domestic and international tourists: “The focus on domestic tourists may not fully capture the behaviors of international visitors, whose diverse cultural backgrounds may yield distinct normative influences [36].” These additions position our findings within a broader global context, enhancing the model’s relevance.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for your submission. Your manuscript presents an important and timely study that investigates sustainable tourism consumption through the integration of the Theory of Planned Behavior (TPB) and the Value–Belief–Norm (VBN) theory in the context of Vietnam. The use of structural equation modeling (SEM), moderation, and mediation techniques is commendable, and your sample provides rich insights into an emerging tourism market.

However, to enhance the overall quality, clarity, and scholarly contribution of the manuscript, I offer the following suggestions:

1. Theoretical Enhancement: The integration of TPB and VBN is a strength, but the literature review would benefit from deeper engagement with recent and international studies on sustainable consumption and green tourism. Consider incorporating the following: Ghouse et al. (2024) on sustainable consumption among Gen Y and Gen Z; Ma et al. (2021) and Li et al. (2024) on green tourism supply chain strategies; Streimikiene et al. (2021) for a broad view on sustainable tourism competitiveness.

2. Clarification of Contributions: While your findings are relevant, the novelty and practical contribution could be more clearly stated in both the introduction and conclusion. Avoid broad claims such as “first empirical study” unless clearly qualified.

3. Contextual Framing: Vietnam provides an excellent case study, but comparisons with other regions or cultural contexts would add depth. Referencing studies that examine tourists' behavior in other parts of Asia or Europe can help position your findings more broadly.

4. Language and Expression: While the manuscript is mostly readable, certain sections would benefit from language polishing to enhance clarity and improve sentence flow. Phrasing and transitions can be refined to reduce redundancy and increase engagement.

5. Reference Quality: The current references are somewhat limited in scope. Please ensure inclusion of high-impact, recent, and regionally diverse studies. This will enhance the manuscript’s academic credibility and appeal.

6. Implications and Future Research: The practical implications could be expanded to offer specific policy recommendations for tourism authorities and marketers. Additionally, you may wish to suggest cross-national or generational comparisons as potential avenues for future research.

Comments on the Quality of English Language

The manuscript is generally understandable and conveys the core ideas clearly. However, there are several areas where the English language could be improved for better clarity, flow, and academic tone. Some sentences are repetitive or awkwardly phrased, and transitions between sections can be made smoother. I recommend a thorough language review or professional proofreading to enhance readability, eliminate redundancy, and ensure consistency in academic writing style.

Improving the language will significantly strengthen the impact and professionalism of the manuscript.

   

Author Response

Comment 1: The integration of TPB and VBN is a strength, but the literature review would benefit from deeper engagement with recent and international studies on sustainable consumption and green tourism.
Response: We appreciate this suggestion to broaden the literature review’s scope. We have enriched Section 2.4 (p. 5) with recent international studies, including Ghouse et al. (2024) on sustainable consumption among Generations Y and Z [new reference], Ma et al. (2021) and Li et al. (2024) on green tourism supply chains [22], and Streimikiene et al. (2021) on sustainable tourism competitiveness [new reference]. We note that “recent advancements, such as Nguyen et al. (2024) on generational influences in Vietnam and Li et al. (2024) on sustainable tourism supply chains, enrich the global discourse [27, 22].” Additionally, a new subsection (2.3: “Integration of TPB and VBN,” pp. 4–5) provides deeper theoretical grounding for the TPB–VBN integration, citing Han [11] and Kiatkawsin & Han [15].

Comment 2: While your findings are relevant, the novelty and practical contribution could be more clearly stated in both the introduction and conclusion. Avoid broad claims such as “first empirical study” unless clearly qualified.
Response: We value this suggestion to sharpen the articulation of our contributions. In the Introduction (p. 2), we now explicitly outline our unique contributions: “This study uniquely: (1) reveals personal norms’ direct effect on SCB, bypassing intention, in a collectivist context; (2) tests TPB–VBN integration in Vietnam’s culturally distinct setting; (3) emphasizes destination attributes’ critical role; and (4) contests intention-driven paradigms, advancing cross-cultural theory.” We have avoided broad claims like “first empirical study,” focusing instead on specific, evidence-based contributions. In the Conclusion (p. 15), we reinforce these contributions with precise statistical evidence (e.g., β = 0.202, p < 0.001 for PN→SCB), ensuring clarity and rigor.

Comment 3: Vietnam provides an excellent case study, but comparisons with other regions or cultural contexts would add depth.
Response: We agree that cross-cultural comparisons enhance the study’s depth. In Section 5.1 (p. 13), we now position our findings against Western contexts, noting that the direct PN→SCB effect “challenges Western-centric TPB–VBN models that prioritize intention as the primary mediator [2].” In Section 5.3 (p. 14), we propose comparisons with other collectivist cultures: “Future studies could test the model in Thailand or Indonesia to assess its cross-cultural applicability,” supported by references to Cheng & Wu [6] and Wu et al. [42]. These additions provide a broader contextual framework for our findings.

Comment 4: While the manuscript is mostly readable, certain sections would benefit from language polishing to enhance clarity and improve sentence flow.
Response: We have conducted a thorough language revision, focusing on the Introduction, Discussion, and Conclusion sections. Complex sentences have been simplified, transitions improved, redundancies eliminated, and terminology standardized (e.g., consistent use of “Consumer Innovativeness” for CI). The manuscript has been reviewed by a professional editor to ensure a clear, engaging, and academic tone, addressing your concerns about phrasing and flow.

Comment 5: The current references are somewhat limited in scope. Please ensure inclusion of high-impact, recent, and regionally diverse studies.
Response: We have significantly updated the reference list with high-impact studies from 2023–2024, including Li et al. (2023) [22], Mathur et al. (2024) [23], Khánh (2024) [14], and Nguyen et al. (2024) [24–27]. These additions incorporate regionally diverse perspectives (Asia, Europe) to enhance the manuscript’s global relevance and academic credibility, addressing your concern about reference scope.

Comment 6: The practical implications could be expanded to offer specific policy recommendations for tourism authorities and marketers.
Response: We have expanded the practical implications in Section 5.2 (p. 14) to include actionable, context-specific recommendations. For instance, we suggest “partnerships with local influencers in destinations like Ha Long Bay to amplify social pressures for sustainability” and propose that “Da Nang’s eco-tourism initiatives could be scaled to include carbon-neutral facilities, attracting sustainability-conscious travelers.” These recommendations are linked to Vietnam’s national tourism law, providing a policy-relevant framework.

Comment on English Quality: Some sentences are repetitive or awkwardly phrased, and transitions between sections can be made smoother.
Response: As addressed in Comment 4, we have undertaken a comprehensive language revision to eliminate redundancies, refine phrasing, and smooth transitions. A professional editor has reviewed the manuscript to ensure a polished, academic style, significantly enhancing readability and professionalism.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

The hypotheses presented in this paper are overly simplistic and lack originality. They essentially reiterate what is already widely known and accepted as fundamental concepts in the fields of sustainable development and environmental protection. The assumptions made in the paper reflect well-established ideas that do not provide any new insights. As a result, the study does not contribute meaningfully to advancing knowledge in these areas.

Given the lack of novelty and the absence of a more nuanced approach to the subject, I do not recommend this paper for publication. It would benefit from further development, particularly in terms of presenting more innovative hypotheses and exploring more complex and under-researched aspects of sustainability and environmental protection.

Author Response

Comment 1: The hypotheses presented in this paper are overly simplistic and lack originality. They essentially reiterate what is already widely known and accepted as fundamental concepts in the fields of sustainable development and environmental protection. The assumptions in the paper reflect well-established ideas that do not provide any new insights. As a result, the study does not contribute meaningfully to advancing knowledge in these areas.
Response: We deeply respect your critical perspective and apologize if the original manuscript did not adequately convey the study’s novel contributions. While our hypotheses build on established theories (TPB and VBN), the study’s originality lies in their integration and application within Vietnam’s collectivist cultural context—a setting underexplored in sustainable tourism research. Specifically, our finding of a direct effect of Personal Norms (PN) on Sustainable Consumption Behavior (SCB), bypassing Behavioral Intention (H4b, β = 0.202, p < 0.001), challenges Western-centric TPB–VBN models that prioritize intention as the primary mediator. This finding, validated through competing model comparisons, represents a significant departure from traditional frameworks.

To clarify this contribution, we have revised the Introduction (p. 2) to articulate our unique contributions: “This study uniquely: (1) reveals personal norms’ direct effect on SCB, bypassing intention, in a collectivist context; (2) tests TPB–VBN integration in Vietnam’s culturally distinct setting; (3) emphasizes destination attributes’ critical role; and (4) contests intention-driven paradigms, advancing cross-cultural theory.” In Section 5.1 (p. 13), we elaborate that “this direct PN–SCB link, grounded in Vietnam’s collectivist culture where implicit moral duties drive actions [13], enriches cross-cultural theory by challenging the universality of intention-based models [15].” We further contextualize this finding with references to Hofstede [13] and Klöckner & Blöbaum [17], highlighting its theoretical significance.

Additionally, we have enriched the hypotheses’ nuance in Section 2.4 (p. 5), exploring under-researched aspects such as the role of Destination Characteristics (DES) and Consumer Innovativeness (CI) in collectivist settings. The reference list has been updated with recent studies (2023–2024), including Mathur et al. (2024) [23] and Li et al. (2023) [22], to strengthen the theoretical and empirical foundation. These revisions demonstrate that our study advances knowledge by offering new insights into sustainable behavior in non-Western contexts, moving beyond the reiteration of established concepts.

Author Response File: Author Response.docx

Reviewer 5 Report

Comments and Suggestions for Authors

This study presents an exploration of sustainable tourism behavior in Vietnam, integrating the Theory of Planned Behavior (TPB) and Value-Belief-Norm (VBN) theory to understand how cultural and psychological factors shape eco-friendly travel choices. While the research offers valuable insights, there are several areas where clarity, structure, and justification could be strengthened to enhance its impact.  

1. The paper rightly identifies Vietnam as a rapidly growing tourism market with significant environmental challenges. However, its relevance to a broader audience could be articulated more explicitly. Vietnam is not just another developing nation with rising tourist numbers—it represents a critical case study in balancing economic growth with sustainability. Moreover, Vietnam’s collectivist culture, shaped by Confucian values and socialist doctrine, offers a fascinating contrast to Western-centric behavioral models. The study finds that personal norms directly influence sustainable behavior, bypassing intention—a deviation from traditional TPB/VBN assumptions. This suggests that in societies where communal harmony and moral duty are deeply ingrained, sustainability interventions might need to emphasize social responsibility over individual choice. These insights could inform policies in other collectivist societies across Asia and beyond.  

2- The current literature review is comprehensive but could be more strategically organized.  
- Foundational Concepts (2.1 & 2.2) → Move to Introduction 
  The definitions of sustainable consumption behavior (SCB), TPB, and VBN are essential for framing the study’s objectives. Placing them early would help readers understand the theoretical basis before diving into methodology.  

- Empirical Gaps (2.3) → Integrate into Methodology
  The discussion of prior research gaps (e.g., overreliance on single-theory models, neglect of destination attributes) naturally leads into the justification for this study’s integrated approach. Positioning it as part of the methodology would strengthen the rationale for model selection.  

3. Sample Composition: Who Are These Tourists? 
The study’s sample of 549 Vietnamese domestic tourists is a solid foundation, but the selection criteria need more transparency.  However, the paper mentions stratified random sampling but doesn’t detail how quotas for region, age, gender, or travel behavior were determined. A table summarizing demographics (e.g., urban vs. rural, income levels, travel frequency) would help assess generalizability. Moreover,  while Vietnam has high internet penetration, relying solely on digital surveys risks excluding less tech-savvy demographics, such as older travelers or rural communities. Acknowledging this limitation—and perhaps suggesting future mixed-methods approaches—would strengthen the methodology.  

4. Linking Theory to Findings. 
One of the most intriguing findings is that personal norms directly affect behavior without influencing intention contradicting standard VBN theory. The discussion briefly attributes this to Vietnam’s collectivist culture but could delve deeper:  

- In societies where actions are driven by implicit moral obligations (e.g., "what my community expects"), individuals may not consciously "intend" to act sustainably—they just do it. This challenges the universality of intention-based models like TPB.  

- If norms matter more than intentions, campaigns should focus on community-based messaging (e.g., "Sustainable travel is our shared duty") rather than individual appeals ("You should recycle").  

This connection between cultural context and behavioral theory is the study’s most original contribution—it deserves more emphasis.  

5. The paper attempts to generalize results but doesn’t fully justify why Vietnam’s case is transferable. To strengthen this:  

- Compare with other collectivist cultures (e.g., Thailand, Japan): Do they show similar norm-driven behaviors? If so, the model may apply across Confucian-influenced or communal societies.  

- Contrast with individualist cultures: Western tourists might rely more on personal attitudes (TPB) than social norms (VBN). Highlighting this dichotomy would underscore the importance of cultural context in sustainability strategies.  

- Acknowledge limits Vietnam’s unique history and rapid tourism growth mean findings may not apply everywhere—but they offer a template for similar emerging economies.  

Author Response

Comment 1: The paper rightly identifies Vietnam as a rapidly growing tourism market with significant environmental challenges. However, its relevance to a broader audience could be articulated more explicitly.
Response: We appreciate this suggestion to strengthen the study’s broader relevance. In the Introduction (p. 2), we now explicitly position Vietnam as a critical case study: “Vietnam’s rapid tourism growth, coupled with its collectivist culture and strong policy commitment to sustainability (e.g., 97% of travelers plan to travel sustainably in 2024 [19, 27]), makes it a pivotal context for studying sustainable tourism behavior.” We further emphasize that “these insights can inform sustainability strategies in other collectivist societies and emerging economies, where cultural norms shape behavior differently from Western models.” This framing underscores Vietnam’s global significance and the study’s applicability beyond its immediate context.

Comment 2: The current literature review is comprehensive but could be more strategically organized.
Response: We agree with this structural suggestion and have reorganized the Literature Review for improved flow. Definitions of Sustainable Consumption Behavior (SCB), TPB, and VBN have been moved to the Introduction (p. 2) to provide early context: “SCB refers to travel choices that minimize environmental, cultural, and social harm [40]; TPB posits that behavior stems from attitudes, norms, and control [2]; VBN emphasizes value-driven moral obligations [35].” The discussion of empirical gaps (formerly 2.3) has been integrated into a new subsection (3.1.1: “Rationale for Model Selection,” p. 6), justifying the TPB–VBN integration: “Prior studies’ overreliance on single-theory models and neglect of contextual factors like destination attributes necessitate an integrated approach [15].” A new subsection (2.3: “Integration of TPB and VBN,” pp. 4–5) further strengthens the theoretical foundation, enhancing logical progression.

Comment 3: The study’s sample of 549 Vietnamese domestic tourists is a solid foundation, but the selection criteria need more transparency.
Response: Thank you for highlighting this methodological concern. We have enhanced transparency in Section 3.2 (p. 6), detailing that “stratified random sampling was employed, with quotas based on national tourism statistics for region, age, and gender [4].” A new table (Table X, p. 6) summarizes demographics (e.g., 52% female, 48% male; 20–40 years predominant; urban vs. rural distribution), ensuring representativeness. We clarify that “surveys were distributed online and in-person at major tourist sites, yielding 549 valid responses (84.5% response rate).” We also acknowledge limitations: “The online format may underrepresent less tech-savvy groups, suggesting future mixed-methods approaches,” addressing generalizability concerns.

Comment 4: One of the most intriguing findings is that personal norms directly affect behavior without influencing intention, contradicting standard VBN theory. The discussion briefly attributes this to Vietnam’s collectivist culture but could delve deeper.
Response: We value this observation and have significantly expanded the discussion of this key finding in Section 5.1 (p. 13): “In Vietnam’s collectivist culture, where communal responsibility is paramount [13], personal norms directly drive SCB (β = 0.202, p < 0.001), bypassing intention, as moral obligations rooted in social harmony override conscious intent.” We position this as “a pivotal contribution that challenges Western-centric TPB–VBN models [2, 15]” and propose that “community-based messaging (e.g., ‘sustainable travel is our shared duty’) may be more effective than individual appeals in such contexts.” References to Hofstede [13] and Klöckner & Blöbaum [17] provide theoretical grounding, emphasizing the finding’s significance.

Comment 5: The paper attempts to generalize results but doesn’t fully justify why Vietnam’s case is transferable.
Response: We agree that transferability requires stronger justification. In Section 5.3 (p. 14), we now compare Vietnam with other collectivist cultures: “Similar norm-driven behaviors may occur in Thailand or Japan, where communal values prevail, suggesting the model’s applicability across Confucian-influenced societies [6].” We contrast this with individualist cultures: “Western tourists may prioritize personal attitudes over norms, highlighting cultural specificity [42].” We acknowledge limitations: “Vietnam’s unique history and tourism growth may limit direct applicability, but its findings offer a template for emerging economies.” These revisions balance generalizability with contextual nuance.

Author Response File: Author Response.docx

Reviewer 6 Report

Comments and Suggestions for Authors

This study offers a comprehensive investigation into sustainable tourism consumption behavior in Vietnam by integrating the Theory of Planned Behavior (TPB) and the Value–Belief–Norm (VBN) theory. While the research addresses an important topic and employs robust methodologies, several critical issues need to be addressed:

-- The integration of TPB and VBN theories is ambitious but may be overly complex for clear interpretation. The study successfully demonstrates the influence of both rational and normative factors on sustainable consumption behavior (SCB), but the direct effect of Personal Norms on SCB without mediating through Behavioral Intention is unusual and requires deeper theoretical explanation. 

-- The study highlights the importance of cultural context in shaping sustainable tourism behavior, particularly in a collectivist culture like Vietnam. However, the findings may not be easily generalizable to other cultural settings. 

-- The measurement of constructs such as Personal Norms and Environmental Awareness could benefit from more detailed operationalization. The study uses validated scales but does not provide sufficient detail on how these constructs are specifically adapted to the Vietnamese context. This may affect the reliability and validity of the findings.

-- The moderation effects of gender and travel experience on the relationships within the model are interesting but need more nuanced interpretation. 

--  While the study provides valuable insights for policymakers and tourism stakeholders, the practical recommendations could be more specific. For example, the suggestion to enhance destination quality and perceived behavioral control is broad and could benefit from more concrete strategies tailored to the Vietnamese tourism industry.

Author Response

Comment 1: The integration of TPB and VBN theories is ambitious but may be overly complex for clear interpretation. The direct effect of Personal Norms on SCB without mediating through Behavioral Intention is unusual and requires deeper theoretical explanation.
Response: We appreciate this observation and have clarified the TPB–VBN integration to ensure interpretability. In Section 2.3 (pp. 4–5), we now explain that “recent studies support TPB–VBN integration, but personal norms’ direct effect on behavior remains underexplored in non-Western contexts [42].” In Section 5.1 (p. 13), we provide a deeper theoretical explanation for the direct PN→SCB effect (β = 0.202, p < 0.001): “In Vietnam’s collectivist culture, implicit moral obligations drive sustainable actions independent of conscious intent, challenging intention-based models [2, 15].” We support this with references to Klöckner & Blöbaum [17] and Hofstede [13], emphasizing that “this direct link, validated through competing model comparisons, enriches cross-cultural theory,” ensuring a robust and accessible explanation.

Comment 2: The study highlights the importance of cultural context in shaping sustainable tourism behavior, particularly in a collectivist culture like Vietnam. However, the findings may not be easily generalizable to other cultural settings.
Response: We concur with this point and have addressed generalizability concerns in Section 5.3 (p. 14): “While Vietnam’s collectivist culture shapes the direct PN–SCB effect, similar dynamics may occur in other communal societies like Thailand or Indonesia, warranting cross-cultural validation [6].” We contrast this with individualist contexts: “Western tourists may exhibit stronger intention-driven behaviors, highlighting cultural specificity [42].” We also acknowledge limitations: “The focus on domestic tourists may not fully capture international visitors’ behaviors, whose cultural backgrounds may differ [36].” These revisions balance transferability with contextual nuance.

Comment 3: The measurement of constructs such as Personal Norms and Environmental Awareness could benefit from more detailed operationalization.
Response: Thank you for this methodological suggestion. In Section 3.3 (p. 7), we have enhanced the operationalization of constructs, providing sample items (e.g., “I feel morally obliged to choose eco-friendly travel options” for PN) and detailing cultural adaptation: “Items were tailored to Vietnam’s collectivist context, emphasizing communal benefits in PN and local environmental concerns in EA.” We also note that “a pilot test with 50 tourists confirmed high internal consistency (Cronbach’s α > 0.80 for all constructs), with minor wording refinements for clarity.” These additions strengthen the reliability and validity of our measurements.

Comment 4: The moderation effects of gender and travel experience on the relationships within the model are interesting but need more nuanced interpretation.
Response: We have expanded the interpretation of moderation effects in Section 4.5 (p. 11), providing nuanced insights. For gender, we clarify that “the influence of Attitude on Intention was significantly stronger among female respondents (β = 0.35, p < 0.01 vs. β = 0.20, p < 0.05 for males), possibly due to greater environmental concern among women [23].” For travel experience, we note that “the effect of PBC on Intention weakens for structured travel (e.g., guided tours) compared to independent travel (β = 0.15, p < 0.05 vs. β = 0.30, p < 0.01), likely due to external constraints.” In Section 5.2 (p. 14), we link these findings to marketing strategies, such as targeting female travelers with sustainability campaigns, enhancing practical implications.

Comment 5: While the study provides valuable insights for policymakers and tourism stakeholders, the practical recommendations could be more specific.
Response: We have significantly expanded Section 5.2 (p. 14) to include specific, actionable recommendations tailored to Vietnam’s tourism industry. For example, we propose “partnerships with local influencers in Ha Long Bay to promote sustainable practices” and suggest that “Da Nang could scale its eco-tourism initiatives by introducing carbon-neutral facilities, aligning with Vietnam’s national tourism law.” These recommendations are grounded in our findings and offer concrete strategies for stakeholders, addressing your concern.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Well done!

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors, congratulations on the additional effort and dedication you have invested in revising your manuscript. The paper now meets all the necessary criteria and reflects a high standard of academic quality.

Reviewer 5 Report

Comments and Suggestions for Authors

I'm happy with the changes made by the authors.

Reviewer 6 Report

Comments and Suggestions for Authors

I think this manuscript has been well revised. The authors has responded all the issues in the last round review.

But I think this manuscript still needs language proof reading before the acceptance.