Dynamic Relationships in Circular Economy Systems: An Integrated Perspective of Resource-Based View, Stakeholder Theory, and System Dynamics

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article is both interesting and highly useful in the Sustainability field. However, to better evaluate the research, I offer the authors some suggestions for improvement.

1. In the introductory chapter (starting with line 71). The paper wants to propose an "intelligent framework" regarding sustainability management in construction, but it is not clear whether the contribution is based on its methodological development or practical application. In this way, the scientific contribution is not clearly delimited, and it is difficult to evaluate the innovative character. I recommend explicitly defining the contribution (conceptual framework and validated implementation).
2. In subchapter 2.3 (starting with line 158). The case study on the construction of a university facility in Egypt is general in nature and does not provide sufficient details regarding the faces used, the way data is collected, what parameters are measured. Since the methodology used does not provide sufficient transparency, I recommend expanding the methodological description and providing additional clarifications regarding the data flow.
3. In chapter 3 (in Results and Discussion). The results presented are from a single case study, without even a comparison with other methods or scenarios. Their presentation does not reflect statistical validation or sensitivity analysis; for example, thus, the validation of the proposed model is very weak. I suggest comparing with existing methods or performing multiple tests (more cases).
4. Regarding figures 1 and 2 (description of the framework). Although they present the architecture of the system, they are done at a schematic level, without detailed identification of the relationships between the elements, nor is there an association with concrete results. This fact leads the figures to an illustrative character rather than a descriptive, scientific one. I propose rewriting the figure captions and explaining the figures in relation to the steps in the methodology.
5. Also, in the Results and Discussion section. Although the paper focuses on sustainability, the indicators used for the evaluation (such as CO2 emissions, costs, energy consumption, etc.) are not clearly defined. The general presentation, without some concrete metrics, does not support the evaluation of sustainability. Please introduce and interpret such metrics.

 

Author Response

Dear Reviewer,

We sincerely appreciate the time and effort you devoted to reviewing our manuscript and providing constructive comments and valuable suggestions. Your feedback has greatly helped us improve the clarity, rigor, and overall quality of the study. We have carefully revised the manuscript accordingly, and all modifications have been incorporated into the revised version.

Comments 1:

In the introductory chapter (starting with line 71). The paper wants to propose an "intelligent framework" regarding sustainability management in construction, but it is not clear whether the contribution is based on its methodological development or practical application. In this way, the scientific contribution is not clearly delimited, and it is difficult to evaluate the innovative character. I recommend explicitly defining the contribution (conceptual framework and validated implementation).

Response 1:

Thank you for pointing this out. We agree with this comment. Therefore, we have revised the Introduction section (approx. Lines 60–80) to explicitly clarify the conceptual, methodological, and empirical contributions of this study. Specifically, we clarified that the study develops an integrated conceptual framework based on circular economy theory, the resource-based view, and stakeholder theory. In addition, we explained that the study introduces a novel methodological approach by transforming causal loop diagrams (CLDs) into a structural equation modeling (SEM) framework for empirical validation. We also clarified that the proposed framework was validated using survey-based statistical analysis. These revisions improve the clarity of the scientific contribution and better highlight the innovative character of the study.

Comments 2:

In subchapter 2.3 (starting with line 158). The case study on the construction of a university facility in Egypt is general in nature and does not provide sufficient details regarding the phases used, the way data is collected, and what parameters are measured. Since the methodology used does not provide sufficient transparency, I recommend expanding the methodological description and providing additional clarifications regarding the data flow.

Response 2:

Thank you for pointing this out. We agree with this comment. Therefore, we have substantially revised the methodology section (approx. Lines 85–120) to improve methodological transparency. Specifically, we added detailed descriptions regarding questionnaire development, pilot testing, sampling procedures, measurement methods, and data collection processes. We clarified that the measurement items were developed based on an extensive literature review and aligned with the constructs derived from the causal loop diagram (CLD) framework. In addition, a pilot test involving 30 respondents was conducted to refine the questionnaire and ensure content validity, followed by the formal survey that yielded 134 valid responses. All variables were measured using a five-point Likert scale. Furthermore, we clarified the two-stage data flow process, including the development of the CLD framework and its transformation into a structural equation modeling (SEM) framework for empirical validation. These revisions strengthen the transparency and replicability of the research design.

Comments 3:

In chapter 3 (in Results and Discussion). The results presented are from a single case study, without even a comparison with other methods or scenarios. Their presentation does not reflect statistical validation or sensitivity analysis; thus, the validation of the proposed model is very weak. I suggest comparing with existing methods or performing multiple tests (more cases).

Response 3:

Thank you for pointing this out. We agree that the original manuscript did not sufficiently emphasize the statistical validation process. Therefore, we clarified that this study does not adopt a single case study approach but instead employs a survey-based empirical design using structural equation modeling (SEM). We revised the Results and Discussion section (Section 4) to strengthen the presentation of confirmatory factor analysis (CFA), model fit indices (e.g., χ²/df, CFI, TLI, RMSEA), and the significance of standardized path coefficients. These revisions demonstrate that the proposed model achieves acceptable levels of reliability, validity, and explanatory power. Furthermore, we clarified that SEM enables the simultaneous testing of multiple causal relationships, thereby providing a stronger empirical basis for model validation. We also acknowledged the limitation of using a single dataset and suggested future studies involving comparative analyses and multiple samples.

Comments 4:

Regarding figures 1 and 2 (description of the framework). Although they present the architecture of the system, they are done at a schematic level, without detailed identification of the relationships between the elements, nor is there an association with concrete results. This fact leads the figures to an illustrative character rather than a descriptive, scientific one. I propose rewriting the figure captions and explaining the figures in relation to the steps in the methodology.

Response 4:

Thank you for pointing this out. We agree with this comment. Therefore, we revised Figure 1 and Figure 2 to improve their scientific clarity and methodological relevance. Specifically, we rewrote the figure captions to explicitly explain the causal relationships, reinforcing and balancing feedback loops, and the transformation process from CLD structures into SEM constructs. In addition, we added further explanations describing how Figure 1 serves as the conceptual foundation of the study and how Figure 2 operationalizes the conceptual relationships into an empirical SEM framework. We also strengthened the connection between the figures and the empirical findings presented in the Results and Discussion section. These revisions improve the scientific interpretability of the figures and ensure that they function as analytical representations rather than purely illustrative diagrams.

Comments 5:

Also, in the Results and Discussion section. Although the paper focuses on sustainability, the indicators used for the evaluation (such as CO2 emissions, costs, energy consumption, etc.) are not clearly defined. The general presentation, without some concrete metrics, does not support the evaluation of sustainability. Please introduce and interpret such metrics.

Response 5:

Thank you for pointing this out. We agree that the original manuscript did not sufficiently clarify the sustainability-related evaluation indicators. Therefore, we revised the Results and Discussion section to provide clearer definitions and interpretations of the sustainability indicators used in this study. Specifically, we clarified that sustainability performance was operationalized using perceptual indicators related to waste reduction, resource efficiency, recycling effectiveness, and environmental performance, measured through a five-point Likert scale. We also expanded the discussion to explain how these indicators reflect the dynamic relationships within the circular economy system and their relevance to sustainability evaluation. These revisions improve the interpretability and practical relevance of the study’s sustainability assessment framework.

Reviewer 2 Report

Comments and Suggestions for Authors

The article proposes an integrated model for analyzing the dynamics of circular economy systems, combining approaches from the circular economy, resource theory, stakeholder theory, and systems dynamics. Based on this integration, the authors develop a causal loop diagram (CLD) that is subsequently transformed into a structural equation model (SEM) for empirical validation using survey data (n=134).

In this context, the results not only reveal positive and significant relationships between resource-based capabilities, design, recycling mechanisms, and resource circulation, but also allow for the identification of a coherent systemic structure in which resource-based design (F1) acts as a driving variable of the system, directly and indirectly influencing resource circulation and waste management. Likewise, the study highlights the mediating role of recycling benefits (F2) in consolidating circular dynamics, as well as the existence of reinforcing feedback loops (R1–R4) that enhance the accumulation of capabilities and balancing loops (B1–B2) that regulate the system through constraints associated with waste management.

Thus, the study offers an interesting approach by translating qualitative systems dynamics structures into a quantitative model, thereby enabling an empirical analysis of the operational logic of the circular economy. However, the following observations should be noted:

1. The article addresses a relevant topic; however, the specific research problem and the gap in the literature it aims to fill are not identified with sufficient clarity. It is recommended to explicitly state which specific limitation of previous studies the study seeks to address.
2. The justification for integrating system dynamics and SEM remains weak. It is suggested to explain in greater depth the methodological contribution compared to traditional approaches (e.g., CLD → SFD vs. CLD → SEM).
3. The theories used are presented descriptively but are not integrated into a common analytical framework. It is recommended to construct a conceptual schema that demonstrates how they interact within the model.
4. It is not clearly established how each theory (VRB, stakeholders, circular economy) translates into observable variables. This creates a disconnect between theory and modeling.
5. The two-stage design (CLD + SEM) is interesting, but lacks methodological traceability. It is unclear how the transition is made from qualitative relationships to quantifiable constructs.
6. It is recommended to detail the operationalization process: How were constructs F1–F4 defined? What criteria were used to group
7. The CLD model is conceptually rich but overly narrative. It is suggested that the textual description be reduced and that diagrams or analytical summaries be prioritized.
8. There is no evidence of a validation process for the CLD (by experts, Delphi method, or comparative literature), which weakens the model’s foundation.
9. Some causal relationships (especially in the loops) appear to be assumed without empirical evidence or specific references.
10. The construction of the constructs (F1–F4) presents problems of conceptual clarity, especially regarding the overlap of some components (e.g., R3 appears in more than one construct).
11. The sample size (n=134) is limited for an SEM model with multiple constructs, which may affect the stability of the estimators.
12. Data collection via social media introduces potential self-selection biases that are not discussed.
13. The profile of the respondents is not described, which limits the interpretation and generalization of the results.
14. The questionnaire items and their source are not presented, which makes it difficult to assess content validity.
15. Although reliability is reported, key indicators such as AVE, CR, or the discriminant correlation matrix are not included.
16. The results report significance but do not present exact values (p-values), which limits transparency.
17. The discussion does not sufficiently compare the results with previous literature, which limits its academic contribution.
18. The methodological limitations (sample size, sampling method, cross-sectional design) should be discussed in greater depth.

Author Response

Dear Reviewer,

We sincerely appreciate the time and effort you devoted to reviewing our manuscript and providing constructive comments and valuable suggestions. Your feedback has greatly helped us improve the clarity, rigor, and overall quality of the study. We have carefully revised the manuscript accordingly, and all modifications have been incorporated into the revised version.

 

Comments 1:
The article addresses a relevant topic; however, the specific research problem and the gap in the literature it aims to fill are not identified with sufficient clarity. It is recommended to explicitly state which specific limitation of previous studies the study seeks to address.

Response 1:
Thank you for pointing this out. We agree with this comment. Therefore, we revised the Introduction section (Lines 75–81) to explicitly clarify the research gap addressed in this study. Specifically, we identified the lack of integration between qualitative system dynamics approaches and empirical validation methods in previous circular economy research. We further clarified that the present study aims to bridge this limitation by integrating causal loop diagrams (CLDs) with structural equation modeling (SEM) for empirical validation.

Comments 2:
The justification for integrating system dynamics and SEM remains weak. It is suggested to explain in greater depth the methodological contribution compared to traditional approaches (e.g., CLD → SFD vs. CLD → SEM).

Response 2:
Thank you for pointing this out. We agree with this comment. Therefore, we strengthened the methodological contribution section (Lines 165–169 and 189–193) by clarifying the differences between traditional CLD-to-SFD approaches and the proposed CLD-to-SEM transformation framework. Specifically, we explained that traditional stock-and-flow diagram (SFD) approaches primarily focus on simulation and dynamic accumulation processes, whereas the proposed CLD-to-SEM approach enables the empirical validation of feedback relationships using measurable variables and statistical analysis.

Comments 3:
The theories used are presented descriptively but are not integrated into a common analytical framework. It is recommended to construct a conceptual schema that demonstrates how they interact within the model.

Response 3:
Thank you for pointing this out. We agree with this comment. Therefore, we added a conceptual explanation in the theoretical framework section to demonstrate how circular economy theory, the resource-based view, stakeholder theory, and system dynamics are integrated into a unified analytical framework. We also clarified the interaction mechanisms among these theoretical perspectives within the proposed model.

Comments 4:
It is not clearly established how each theory (RBV, stakeholders, circular economy) translates into observable variables. This creates a disconnect between theory and modeling.

Response 4:
Thank you for pointing this out. We agree with this comment. Therefore, we revised the methodology section to clarify how each theoretical perspective was operationalized into measurable constructs. Specifically, we explained how resource-based theory was linked to resource design advantage (F1), circular economy theory to resource circulation and recycling mechanisms (F2 and F3), and stakeholder-related sustainability behaviors to waste reduction control (F4).

Comments 5:
The two-stage design (CLD + SEM) is interesting, but lacks methodological traceability. It is unclear how the transition is made from qualitative relationships to quantifiable constructs.

Response 5:
Thank you for pointing this out. We agree with this comment. Therefore, we enhanced methodological transparency by providing a clearer explanation of the transition process from qualitative CLD relationships to quantifiable SEM constructs (Lines 400–406). Specifically, we detailed the two-stage research process, including the identification of feedback structures in the CLD and their subsequent transformation into measurable latent variables and structural relationships within the SEM framework.

Comments 6:
It is recommended to detail the operationalization process: How were constructs F1–F4 defined? What criteria were used to group them?

Response 6:
Thank you for pointing this out. We agree with this comment. Therefore, we expanded the construct development section to clarify the operationalization process of F1–F4. Specifically, we explained that the constructs were defined based on theoretical synthesis, causal feedback relationships, and conceptual similarities identified within the CLD framework.

Comments 7:
The CLD model is conceptually rich but overly narrative. It is suggested that the textual description be reduced and that diagrams or analytical summaries be prioritized.

Response 7:
Thank you for pointing this out. We agree with this comment. Therefore, we revised the CLD description section by reducing repetitive narrative explanations and strengthening the analytical interpretation of Figure 1 and related feedback structures. Additional explanatory summaries were also added to improve readability and clarity.

Comments 8:
There is no evidence of a validation process for the CLD (by experts, Delphi method, or comparative literature), which weakens the model’s foundation.

Response 8:
Thank you for pointing this out. We agree that the original manuscript did not sufficiently clarify the theoretical validation process of the CLD. Therefore, we strengthened the explanation by clarifying that the CLD structure was developed based on extensive literature synthesis, systems thinking analysis, and prior system dynamics studies. Additional supporting references were also included to reinforce the conceptual foundation of the model.

Comments 9:
Some causal relationships (especially in the loops) appear to be assumed without empirical evidence or specific references.

Response 9:
Thank you for pointing this out. We agree with this comment. Therefore, we added additional supporting references and theoretical explanations for several causal relationships within the reinforcing and balancing feedback loops to strengthen the empirical and theoretical justification of the model structure.

Comments 10:
The construction of the constructs (F1–F4) presents problems of conceptual clarity, especially regarding the overlap of some components (e.g., R3 appears in more than one construct).

Response 10:
Thank you for pointing this out. We agree with this comment. Therefore, we revised the descriptions of constructs F1–F4 to improve conceptual clarity and better explain the relationships among reinforcing and balancing feedback loops. We also clarified the rationale for the inclusion of overlapping feedback mechanisms within multiple constructs.

Comments 11:
The sample size (n=134) is limited for an SEM model with multiple constructs, which may affect the stability of the estimators.

Response 11:
Thank you for pointing this out. We agree that sample size is an important consideration in SEM analysis. Therefore, we added additional discussion regarding sample size limitations and clarified that the sample size meets the minimum recommended requirements for SEM analysis according to prior methodological studies. We also acknowledged this limitation in the conclusion section.

Comments 12:
Data collection via social media introduces potential self-selection biases that are not discussed.

Response 12:
Thank you for pointing this out. We agree with this comment. Therefore, we added additional discussion regarding potential self-selection bias associated with social media-based sampling and acknowledged this limitation in the revised manuscript.

Comments 13:
The profile of the respondents is not described, which limits the interpretation and generalization of the results.

Response 13:
Thank you for pointing this out. We agree with this comment. Therefore, we added additional descriptions of respondent profiles, including demographic and participation characteristics, to improve the interpretability and generalizability of the findings.

Comments 14:
The questionnaire items and their source are not presented, which makes it difficult to assess content validity.

Response 14:
Thank you for pointing this out. We agree with this comment. Therefore, we added additional explanations regarding questionnaire items and their theoretical sources. We also clarified that the measurement items were adapted from prior literature and aligned with the constructs identified in the CLD framework.

Comments 15:
Although reliability is reported, key indicators such as AVE, CR, or the discriminant correlation matrix are not included.

Response 15:
Thank you for pointing this out. We agree with this comment. Therefore, we strengthened the statistical reporting by including additional validity indicators, including Average Variance Extracted (AVE) and Composite Reliability (CR), to improve the robustness of the measurement model assessment.

Comments 16:
The results report significance but do not present exact values (p-values), which limits transparency.

Response 16:
Thank you for pointing this out. We agree with this comment. Therefore, we revised the Results section to provide more detailed statistical reporting, including exact significance levels and standardized path coefficients, in order to improve transparency and interpretability.

Comments 17:
The discussion does not sufficiently compare the results with previous literature, which limits its academic contribution.

Response 17:
Thank you for pointing this out. We agree with this comment. Therefore, we expanded the discussion section by strengthening comparisons between the present findings and prior literature related to circular economy systems, system dynamics, and resource-based perspectives.

Comments 18:
The methodological limitations (sample size, sampling method, cross-sectional design) should be discussed in greater depth.

Response 18:
Thank you for pointing this out. We agree with this comment. Therefore, we expanded the limitations section to discuss methodological limitations in greater depth, including sample size, social media-based sampling, and the cross-sectional nature of the survey design. We also proposed future research directions involving longitudinal and comparative studies.

 

Reviewer 3 Report

Comments and Suggestions for Authors

This is an interesting paper, with a very strong theoretical foundation grounded in traditional literature.

You mention software such as Vensim, which researchers can use to develop stock-and-flow diagrams (SFDs) for model validation, structural testing, and dynamic simulation analysis [1,27,36,37]. Could you provide examples of additional software, or explain why this particular tool was selected?

How can models of reuse or repair be incorporated into the proposed cycles?

Please provide more details about the formal survey: Was the number of responses sufficient? Was it anonymous? If not, who was it targeted at? Could you also provide a link to the survey?

Although the limitations of the study have already been mentioned, could you propose any policy recommendations—not only for companies but also for regional or country or global policy?

Could you expand the discussion in relation to the cited literature review?

A list of abbreviations would also be welcome.

Author Response

Dear Reviewer,

 

We sincerely appreciate the time and effort you devoted to reviewing our manuscript and providing constructive comments and valuable suggestions. Your feedback has greatly helped us improve the clarity, rigor, and overall quality of the study. We have carefully revised the manuscript accordingly, and all modifications have been incorporated into the revised version.

 

Comments 1:
You mention software such as Vensim, which researchers can use to develop stock-and-flow diagrams (SFDs) for model validation, structural testing, and dynamic simulation analysis [1,27,36,37]. Could you provide examples of additional software, or explain why this particular tool was selected?

Response 1:
Thank you for pointing this out. We agree with this comment. Therefore, we revised Section 2.4 (Lines 160–164) to clarify the rationale for selecting Vensim DSS in this study. Specifically, we explained that Vensim DSS was selected because of its strong capability in representing causal loop diagrams (CLDs), handling feedback structures, and supporting flexible system dynamics modeling and validation. In addition, we added examples of alternative system dynamics software tools, including Stella Architect and AnyLogic, which are also widely used in system dynamics and simulation research. These revisions strengthen the methodological justification of the software selection.

Comments 2:
How can models of reuse or repair be incorporated into the proposed cycles?

Response 2:
Thank you for pointing this out. We agree with this comment. Therefore, we expanded the discussion in Section 3.1 (Lines 202–206) to clarify how reuse and repair mechanisms can be integrated into the proposed reinforcing feedback loops (R3 and R4). Specifically, we explained that reuse, remanufacturing, refurbishment, and repair processes enable products to re-enter the circular economy system, thereby extending product life cycles, enhancing resource circulation, and reducing the dependence on new resource inputs. These revisions strengthen the circular economy perspective of the proposed model.

Comments 3:
Please provide more details about the formal survey: Was the number of responses sufficient? Was it anonymous? If not, who was it targeted at? Could you also provide a link to the survey?

Response 3:
Thank you for pointing this out. We agree with this comment. Therefore, we revised the methodology section (Section 3, Lines 187–192) to provide additional details regarding the survey design and data collection procedures. Specifically, we clarified that the survey was conducted anonymously and distributed through online platforms. The final sample consisted of 134 valid responses, which meets the minimum recommended sample size requirements for structural equation modeling (SEM) analysis according to prior methodological literature. We also added descriptions regarding the target respondents and measurement approach. Due to privacy and confidentiality considerations, the questionnaire is available upon reasonable request from the corresponding author.

Comments 4:
Although the limitations of the study have already been mentioned, could you propose any policy recommendations—not only for companies but also for regional or country or global policy?

Response 4:
Thank you for pointing this out. We agree with this comment. Therefore, we expanded the conclusion section (Section 5, Lines 557–561) to include policy implications at multiple levels. In addition to firm-level strategies, we added policy recommendations for governments and regulatory institutions, including circular economy incentive mechanisms, subsidies for green innovation, and regulatory frameworks supporting recycling systems and sustainable resource circulation. We also discussed the importance of international cooperation and standardized sustainability regulations at regional and global levels. These revisions strengthen the practical and policy relevance of the study.

Comments 5:
Could you expand the discussion in relation to the cited literature review?

Response 5:
Thank you for pointing this out. We agree with this comment. Therefore, we expanded the discussion section (Section 4.4, Lines 498–500) to strengthen the linkage between the empirical findings and prior literature related to system dynamics, circular economy theory, stakeholder theory, and the resource-based view. Specifically, we added additional comparative discussions to explain how the present findings support and extend previous studies regarding feedback mechanisms, resource circulation, and sustainability system behavior. These revisions strengthen the theoretical contribution of the study.

Comments 6:
A list of abbreviations would also be welcome.

Response 6:
Thank you for pointing this out. We agree with this comment. Therefore, we added a list of abbreviations at the end of the manuscript to improve readability and clarity for readers.

 

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Based on my comments on the article, I see significant improvement and great potential in the explanation of the topics covered, incorporating all the variables necessary for the project’s completion.

There is evidence of improvement in the presentation of the methodology and results of the article, addressing and resolving the comments raised. Therefore, the article is accepted in its latest version.