Quantifying the Effect of Non-Tariff Measures on Imports of Saudi Arabia Using a Panel ARDL Gravity Model

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Quantifying the impact of non-tariff measures on Saudi Arabia's imports using panel ARDL gravity model

This article extends the classic literature on port operation optimization from the perspective of carbon emissions. The overall analysis seems to be correct; Simulation is used to generate insights.

This article quantitatively analyzes the impact of non-tariff measures on Saudi Arabia's import trade through the Panel ARDL gravity model. This study utilized panel data from 2000 to 2022, covering four major trading regions, and conducted a detailed analysis of both long-term and short-term impacts. These conclusions provide valuable insights for Saudi Arabia's policy makers in adjusting trade policies.

My overall impression is that the paper is clear and well structured. The research method is reasonable and the results are presented logically. I am very interested in your research topic, especially the application of panel ARDL model in analyzing non-tariff measures. However, there are still some modifications that need to be made before accepting this manuscript. My comment is as follows:

#Comment 1: The model assumptions in this article are too simplistic because they assume that the impact of NTM on all trading partners is the same. This may not fully reflect reality, as the nature and impact of NTMs in different countries/regions may vary greatly. Suggest introducing more interaction terms or conducting subgroup analysis to capture the heterogeneous effects of NTM in different countries or regions.

#Comment 2: Although the article found that non-tariff measures have a significant negative impact on imports in the short term, there is a lack of detailed explanation of the mechanisms behind this short-term impact. For example, non-tariff pressure relief mechanisms may lead to higher compliance costs or longer customs clearance times, but these aspects have not been thoroughly discussed. It is suggested to further analyze the specific mechanisms by which non-tariff measures affect imports, such as through case studies or surveys, to understand how companies respond to non-tariff measures and how these reactions affect their import decisions.

#Comment 3: This article assumes that the long-term impact of NTM is stable, but in reality, the situation may be more complex. For example, with technological advancements and policy adjustments, the long-term impact of non-tariff measures may change. Suggest introducing time trend variables or conducting stage analysis to capture the dynamic changes in the long-term impact of NTM.

#Comment 4: The policy proposal of "reducing the negative impact on international trade" lacks specific content on which measures or departments should be adjusted. It would be beneficial to propose specific policy adjustment suggestions based on the classification of non-tariff measures and balance trade liberalization with considerations of national security and health.

Author Response

Thank you for taking the time to review this manuscript. For our response to your comments, please see the attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript addresses a relevant and timely topic; however, several substantive issues require clarification or improvement to enhance the scientific rigor and policy relevance of the study:

1. The paper does not clearly state the research questions or hypotheses that guide the empirical approach. For example, in section 1 (Introduction) and section 4.2 (Gravity Model), the model is described and the direction of the analysis is suggested, but no testable hypothesis is formulated (e.g., "NTMs have a negative impact on imports"). Clarification of these hypotheses would improve the methodological consistency of the study.
2. Treating non-tariff measures with a dummy variable (0 before 2005, 1 after 2005) is an oversimplification of a complex phenomenon. This choice reduces the accuracy of the estimates and risks masking real variations in NTMs over time and across sectors. For example, section 4.2 states: "NTM is included as a dummy variable starting from the date of application," but no rigorous justification is provided for this choice.
3. The conclusions drawn in section 7 generalize the negative effects of NTMs without sufficiently discussing the interregional variations highlighted in section 5.4 (cross-sectional ECM). For example, the effect of NTMs on imports from the GCC is stronger than that on the EU or NA, but this is not critically discussed. Furthermore, the policy recommendations are vague and not anchored in data.
4. Although relevant studies are cited (e.g., Anderson and van Wincoop, Beghin et al.), the literature review in Section 3 is not used effectively to justify the choice of methodology or to interpret differences in results. For example, there is no discussion of why the results of the paper differ from or confirm those of Shepotylo (2016) or Ghodsi et al. (2017), although these are cited. A more thorough integration of the literature would support the external validity of the conclusions.

Author Response

Thank you for taking the time to review this manuscript. For our response to your comments, please see the attached file

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The “Literature Review” section is too narrow. A small number of publications have been cited. The review should be expanded to include studies. You can also cite studies from other regions, as well as studies that are similar in some way but use different methods/tools. It is worth presenting the context of the research undertaken by the author/authors in this section in more detail.

The “Discussion” section, if it is possible to refer to a larger number of publications, is worth expanding.

The next section is “Conclusions”. It is quite modest. I suggest expanding the formulated conclusions. Additionally, the “Limitation of the Study” section should be a subsection of the “Conclusions” section. It is too small to be a separate section of the article.

As for the empirical part, it is well prepared. The research methodology has also been presented well.

The language of the article is correct. No language errors were found.

The cited publications are consistent with the discussed topic. However, I recommend citing more studies.

As for the editorial side, the article is properly prepared. It was prepared in accordance with the journal's guidelines.

Overall, the article is well written. However, it requires several corrections. This mainly concerns expanding the literature review. Expanding the conclusions (making them more broad), and also incorporating the limitations of the study into the conclusions.

Author Response

Thank you for taking the time to review this manuscript. For our response to your comments, please see the attached file

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

This paper extends the empirical literature on trade barriers by quantifying the impact of Non-Tariff Measures (NTMs) on Saudi Arabia's imports, a gap in existing research. Using a Panel ARDL Gravity Model with data from 2000–2022 across four major trading regions (GCC, EU, Asia, North America), the study provides robust evidence of NTMs' short- and long-term effects.

The paper is methodologically rigorous, leveraging panel ARDL to address cointegration and dynamic effects. Overall, the manuscript neesds a minor revision. Specifically, my comments are as follows:

#Comment 1: While Table 8 (cross-sectional ECM) shows regional variations in NTM coefficients, the core model still treats NTMs as a binary dummy. This assumes uniform intensity across all measures and sectors, which oversimplifies reality.

#Comment 2: The added text (lines 123–124) only generically mentions compliance costs. It lacks concrete examples (e.g., case studies) or empirical evidence on how NTMs translate to delays/costs (e.g., customs bottlenecks, testing backlogs).

#Comment 3: The added sectoral focus (textiles, food, etc.) is a step forward but remains vague. No prioritization or actionable steps are provided.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The author's responses adequately cover the main observations, providing important additions regarding the formulation of hypotheses, the justification of the methodology and the interpretation of the results. However, in order to give the manuscript a more solid argumentative and scientific validity, I believe that several bibliographical sources should be added to support the analysis, in particular through methodological justification: the use of the dummy variable for NTMs is recognised as a solution that is not widely accepted in the literature.
Thus, I believe that more bibliographic sources should be added to support the analysis, in particular through methodological justification: the use of the dummy variable for NTMs is recognised as a compromise solution, but the argumentation could be strengthened.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

After corrections, the article meets the requirements set by the Journal and may be published.

Author Response

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Author Response File: Author Response.pdf