Impact of Producer Service Agglomeration on Carbon Emission Efficiency and Its Mechanism: A Case Study of Urban Agglomeration in the Yangtze River Delta

Round 1

Reviewer 1 Report

Please see the attached file for details of my comments.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 1 Comments

Thank you very much for your helpful comments on our paper. Corresponding to your suggestions, in the revision we have responded as follows:

Point 1: The authors should provide basic statistics on the conditions of economic growth and carbon emissions in the Yangtze River Delta area and compare them with other parts of China to justify the significance of conducting a case study for the area.

Response 1: We give basic statistics on economic growth and carbon emissions in the YRD(Yangtze River Delta) region. In terms of economic growth, the YRD region is an important strategic area for China’s economic development. In particular, the gross domestic product (GDP) of the YRD region was 27.61 trillion yuan (about 4.28 trillion dollars) in 2021, generating 24.14% of China’s GDP on less than 4% of its land area, which means that the YRD region makes an important contribution to China’s economic growth. Carbon emissions in the YRD region are high, with overall emission levels already accounting for more than 20% of China’s total carbon emissions. During the “13th Five-Year Plan period”, the average annual growth rate of carbon emissions in the YRD region was as high as 2.4%. This means that low-carbon development is critical to the YRD region. In conclusion, the improvement of carbon emission efficiency (CEE) in the YRD region can not only make an important contribution to China’s economic development, but also provide an important help to achieve “carbon peaking and carbon neutrality”. Therefore, we believe it is critical to conduct a detailed study of the YRD region. Please see line31-47 for details.

Point 2: More details of the characteristics of the Yangtze River Delta area should be explained. It would be nice to include a map showing the regions that belong to this delta too.

Response 2: We made a geographical location map of the YRD region through ArcGIS 10.7, which contains Zhejiang Province, Anhui Province, Jiangsu Province, and Shanghai, with a total of 41 cities at the prefecture level and above . Please see page 2 for details.

Point 3: It should also provide explanations on why the hypotheses stated might stand for the Yangtze River Delta area and how it might be different in other parts of China.

Response 3: We focus on making the following adjustments to hypothesis 1 of this paper. First, the cluster life cycle theory suggests that the different development stages make the effect of industrial clusters differ, which also provide the basis for the nonlinear theory proposed in this paper. Second, the relevant literature pointed out that the insufficient agglomeration of producer services at this stage makes it difficult to show the economies of scale and technology spillover effects of APS (Han and Xie, 2017). Therefore, instead of producing the expected carbon reduction effect, the agglomeration of producer services (APS) will aggravate the regional carbon emission. This study is based on the YRD region, which has superior economic development conditions and a relatively high degree of the APS, so that the economies of scale and technology spillover effects can be brought into full play (Shen et al., 2020). Considering the heterogeneity, this paper proposes a U-shaped relationship between APS and CEE in the YRD region (first inhibiting, then promoting). Please see page4 line146-164 for details.

Point 4: It would be nice to separate the literature review since there seem to be quite a few studies investing similar topics for China.

Response 4: We split the original introduction into two sections: the introduction (section 1) and the literature review (section 2) to make the structure of the paper clearer. And we have also integrated the content of these two sections. Please see page 1-3 for details.

Point 5: Equations (4) and (8) have been cut between the lines.

Response 5: We have reviewed all the equations in the paper. Among them, we revised the problems with equation (4) and (8) (Now are equation (7) and (11)). Please see equation (7) on page 6 and equation (11) on page 7 for details.

Point 6: Ln322-324, “CEE and APS are characterized by a constantly emerging homogeneous distribution, 322 showing a spatial trend of being low in the west and high in the east but balanced between 323 the north and south.” It is very difficult to see this from Figure 2. Please add supplemental information to the graph so that the readers can see which axis represents the direction.

Response 6: First, after considering the logical order of the section 5 and combining your suggestions from the mapping, we rearranged the Section 5 as follows: 5.1.Spatial correlation analysis, 5.2.Model testing and selection, 5.3.Spatial effect analysis, and 5.4.Robustness and endogeneity tests, in order to show the spatial econometric analysis process more clearly and accurately. Second, we removed the method of trend analysis from the previous version, and we visualized the spatial distribution of carbon emission efficiency (CEE) in each year by drawing maps of the YRD region to avoid the problem of unclear mapping that occurred in the past. Please see pages 10-11 for details.

Point 7: Ln340. It is very difficult to see a U-shaped relation in Figure 3. Consider plotting differently.

Response 7: Thank you for your suggestion. With a comprehensive consideration of section5, we adjust the relevant contents of this part to make it more in line with the spatial econometric analysis process and the overall logical arrangement. We describe it in other ways on pages 10-16.

Point 8: The six models in Table 6 should have been explained in the methods section. It seems the explanation for Model (6) is missing.

Response 8: We have added the explanation of the sixth model in Table 6 (Now is Table 7). The sixth model indicates that technological innovation positively affects the carbon emission efficiency (CEE). Also, we have reviewed all parts of the model explanations. Please see page 16 line 509-510 for details.

Point 9: The methods for the MAR, Jacobs, and Porter should have been introduced in the methods section. Consider moving to the previous section.

Response 9: We moved the settings for MAR, Jacobs, and Porter externality to Section 4.2 Variable selection, and adjusted the ordinal number of the equation. Please see page 8 equation(13)-(15) for details.

Point 10: Before ln510. I think the Equation numbers are 11 through 13.

Response 10: We checked the ordinal numbers of all equations in the paper and revised the problematic areas.

Point 11: It is difficult to figure out if the results were specific to the YRD or they could stand also in other parts of China.

Response 11: To highlight the heterogeneity of the findings and policy recommendations for the YRD region, we made the following adjustments. First, there is a U-shaped relationship between agglomeration of producer services (APS) and carbon emission efficiency (CEE) in the YRD region. Therefore, for cities that have not crossed the inflection point, they should expand the scale of production service industry agglomeration and realize the positive externality of production service industry agglomeration as soon as possible. For cities that have crossed the inflection point, they should focus on the optimization of the internal structure of the producer services and promote the producer services’ scale in the surrounding areas through the spatial spillover effect. Please see page20-21 line614-631 for details. Second, we further divide the cities under each threshold range to highlight the variability of cities within the YRD region (Please see page 17 Table 8 Pannel C for details). At the same time, in the policy recommendation section, we also further provide heterogeneous policy recommendations for the two categories of cities that cross the threshold and those that do not, highlighting the relevance of this study to the YRD region. Please see page21 line648-670 for details.

Point 12: Limitations of the study should be included in the conclusion section since the journal required to include limitations.

Response 12: We add two aspects to the limitations of this study and directions for future research at the end of the paper.

In terms of direct effects, the impact of agglomeration of producer services (APS) on carbon emission efficiency (CEE) may also vary due to the large number of productive service industry segments and the different knowledge and technology intensity of different industries. The next studies can further provide more microscopic and heterogeneous evidence on the impact of APS on CEE from the perspective of producer service industry segments.

In terms of spatial spillover effects, we believe that the spatial spillover boundaries of APS on CEE can be further investigated in the future, which is particularly important for the synergistic development of cities in the YRD region with different geographical distances. Please see page 21-22 line 672-695 for details of the above changes.

Point 13: Please change the reference style to meet the standard style suggested by the journal in the next revision.

Response 13: We have checked all formatting issues in the article and made changes to the formatting of the references section. Please see page 22-25 for details.

Reviewer 2 Report

Dear Authors,

Your article examines a topic of current interest and general interest. But, there are a few things you need to improve. These are:

* An additional argumentation of the choice of the study area is needed. A description of the physical-geographical and economic characteristics of the study area. A map of the geographical location of the study area in China and the presence of the 41 cities classified by population would represent added value for the article. What are the 41 cities? What are ”mega-cities” and what are ”big cities”? Why are they important? What is the criterion according to which this importance is established? As a reader, one feels the need for such a description and the location of the study area.

* The paragraph from lines 89-91 I do not think it is necessary to remain in the article. It is a classic / specific structure of a scientific article.

* Section 2 requires citation support. Being a theoretical framework, it must be supported by several bibliographical references. 

* Check the spacing throughout the article.

* Figure 1 is difficult to read. Better clarity is needed and therefore this aspect needs to be remedied. Does the structure of this figure belong to you or is it adapted to another model? If the figure is adapted, mention modified after ...

* Section 3.1.1. must be supported by citations.

* Not all symbols in section 3 are explained. Fix this issue!

* Write the full name first, put the acronym in parentheses and then you can use the acronym, as you did in most cases. Not everyone is used to the acronym GDP ... see line 251. Fix this aspect, where appropriate.

* Convert between yuan and euro or US dollar, so that the values are perceived by the readers.

* The titles of sections 4. and 4.1. should appear on the next page.

* Check the notation of the images that make up figure 2. You missed APS in 2019. Invert the acronyms in the title of Figure 2.

* Tables 3 and 4 must be brought in the article closer to the paragraphs that refer to them. In Table 3, in the first column, fix the problem of word spaces. Below table 4, put a legend or a note and write what each acronym means. It is difficult to return to the text to know what each acronym represents.

* To the equations in section 5.3. not all symbols are explained.

I wish you success with your article.

Sincerely,

Author Response

Response to Reviewer 2 Comments

Thank you very much for your helpful comments on our paper. Corresponding to your suggestions, in the revision we have responded as follows:

Point 1: An additional argumentation of the choice of the study area is needed. A description of the physical-geographical and economic characteristics of the study area. A map of the geographical location of the study area in China and the presence of the 41 cities classified by population would represent added value for the article. What are the 41 cities? What are “mega-cities” and what are “big cities”? Why are they important? What is the criterion according to which this importance is established? As a reader, one feels the need for such a description and the location of the study area.

Response 1: Thanks to your suggestion, we have made the following adjustments to the introduction. First, the visualization software ArcGIS10.7 is used to make a geographical location map of the YRD region to give readers a clearer understanding of the research area of this paper . Second, the population of the city district in 2014 was used as the standard, and the city size was divided according to the “Notice on Adjusting Criteria of City Size Classification” issued by the State Council in 2014. Third, we give basic statistics on economic growth and carbon emissions in the YRD region to highlight the importance of studying the CEE in the YRD region. Fourth, based on the above changes, we split the original introduction into two sections: the introduction (section 1) and the literature review (section 2) to make the structure of the paper clearer. In addition, we have adjusted the contribution to the end of the section2 literature review. Please see page 1-2 for details.

Point 2: The paragraph from lines 89-91 I do not think it is necessary to remain in the article. It is a classic / specific structure of a scientific article.

Response 2: Based on your suggestion, we have removed lines 89-91 from the article. Moreover, we have organized and optimized the introduction and literature review sections.

Point 3: Section 2 requires citation support. Being a theoretical framework, it must be supported by several bibliographical references.

Response 3: In our revision process, we have added citations throughout the article and made detailed changes to the section of the theoretical framework that you mentioned. For example, such as the studies of Yuan et al.(2022), Han et al.(2018) and Wang et al.(2020). Please see page 3-5 for details.

Point 4: Check the spacing throughout the article.

Response 4: We reviewed the line spacing throughout the article during the revision process and corrected any problematic areas.

Point 5: Figure 1 is difficult to read. Better clarity is needed and therefore this aspect needs to be remedied. Does the structure of this figure belong to you or is it adapted to another model? If the figure is adapted, mention modified after ....

Response 5: Figure 2 (The original is Figure 1, now is the Figure 2) is our own drawing, which is a visualization of the theoretical framework of the article. We have adjusted the clarity of this figure based on your suggestion. Please see page5 Figure2 for details.

Point 6: Section 3.1.1. must be supported by citations.

Response 6: We have added references in the section 4.1.1 Spatial Durbin model (The original is the section 3.1.1, now is the section 4.1.1). In addition, we have reviewed the references of section 4.1.2 Mediating effect model and section 4.1.3 Threshold effect model and made additions to the references in these two sections as well. Please see page 5-7 for details.

Point 7: Not all symbols in section 3 are explained. Fix this issue!.

Response 7: We have reviewed all symbolic explanations in section 4 Methodology and data (The original is the section 3, now is the section4) and revised the sections where symbolic explanations were missing. Please see page 5-10 for details.

Point 8: Write the full name first, put the acronym in parentheses and then you can use the acronym, as you did in most cases. Not everyone is used to the acronym GDP ... see line 251. Fix this aspect, where appropriate.

Response 8: We have reviewed all similar issues in the full article. Among them, the issue you mentioned can be found in page1 line37 for details.

Point 9: Convert between yuan and euro or US dollar, so that the values are perceived by the readers.

Response 9: We have focused on converting the statistical units covered in the section 1 Introduction to give the reader a more intuitive sense of monetary values. Please see page1 line37-38 for details.

Point 10: The titles of sections 4. and 4.1. should appear on the next page.

Response 10: We have revised this issue. Please see page10 line346-347 for details (The original are sections 4. and 4.1., now are sections 5. and 5.1.).

Point 11: Check the notation of the images that make up figure 2. You missed APS in 2019. Invert the acronyms in the title of Figure 2.

Response 11: We combined your suggestion of mapping and this problem, and we made the following adjustments in section 5.1 (Spatial correlation analysis). First, the spatial correlation of CEE in the YRD region was measured to use the Moran’I and Geary’C indices. Second, based on your suggestions for mapping, ArcGIS10.7 was used to map the spatial distribution of CEE in the YRD region from 2005-2019, which more intuitively reflects the distribution of CEE values of each city in each year. Please see page10-11 line347-377 for details of the above changes.

Point 12: Tables 3 and 4 must be brought in the article closer to the paragraphs that refer to them. In Table 3, in the first column, fix the problem of word spaces. Below table 4, put a legend or a note and write what each acronym means. It is difficult to return to the text to know what each acronym represents.

Response 12: We have made the following adjustments to the structure of Section 5 (Empirical analysis).First, Section5 is specifically organized as follows: 5.1.Spatial correlation analysis, 5.2.Model testing and selection, 5.3.Spatial effects analysis, and 5.4.Robustness and endogeneity tests. It can allow the tables to be closely linked to the articles involved. Second, we also made adjustments to the format of the tables to make them conform to the requirements of the journal. Finally, we have added explanations for each variable in the notes below Table 4 (Now it’s Table 5) to make it easier for readers to read. Please see pages 10-16 for details of the above changes.

Point 13: To the equations in section 5.3. not all symbols are explained.

Response 13: We have reviewed all similar issues in the article. We have revised the problem you mentioned in detail on page 8 lines 289-296 (The equation was originally in Section 5.3, but is now adjusted to Section 4.2.2 for uniformity of variable settings).

Round 2

Reviewer 1 Report

I think the paper has improved significantly but some minor issues related to the layout of the manuscript require to be revised.

1. Figure 3 is too tiny for the readers to see. I recommend having it in one or two pages.

2. This journal does not allow to have footnotes so I hope you can embed the notes into the main text.

Author Response

Response to Reviewer 1 Comments

Thank you very much for your helpful comments on our paper. Corresponding to your suggestions, in the revision we have responded as follows:

Point 1: Figure 3 is too tiny for the readers to see. I recommend having it in one or two pages.

Response 1: Based on your suggestion, we bolded and enlarged the font in Figure 3 and placed it on the full page of 12. Please see page 12 lines 379-383 for details.

Point 2: This journal does not allow to have footnotes so I hope you can embed the notes into the main text.

Response 2: Thank you for your reminder. We have modified the footnotes in the form of comments in Figure 1. Please see page 2 lines 61-68 for details.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors,

I appreciate your effort to improve the article. There are still small aspects to improve. There are:

* The writing in the legends of figure 1 should be a little bigger, to be read easily.

* Bring figure 2 closer to the paragraph where you refer to it. If not, in sections 3.2. and 3.3. refer again to figure 2.

* In figure 3, I advise you to remove the numbering with letters and leave only the years. Also, you have the same legend for all the maps in the figure ... therefore, leave only one for all the maps so that it can be read. As Figure 3 shows, the legend cannot be read.

I wish you all the best,

Author Response

Response to Reviewer 2 Comments

Thank you very much for your helpful comments on our paper. Corresponding to your suggestions, in the revision we have responded as follows:

Point 1: The writing in the legends of figure 1 should be a little bigger, to be read easily.

Response 1: Thank you for your suggestion. First, we bolded and enlarged the font of the legend in Figure 1. Second, we also reset the font in Figure 1 to match the font of the text.

Point 2: Bring figure 2 closer to the paragraph where you refer to it. If not, in sections 3.2. and 3.3. refer again to figure 2.

Response 2: Thank you for your reminder. We refer to Figure 2 again in sections 3.2 and 3.3. Please see page 4 line 177 and page 5 line 200 for details.

Point 3: In figure 3, I advise you to remove the numbering with letters and leave only the years. Also, you have the same legend for all the maps in the figure ... therefore, leave only one for all the maps so that it can be read. As Figure 3 shows, the legend cannot be read.

Response 3: Thank you for your suggestion. First, we have enlarged and bolded the font in Figure 3. Second, we removed the numbering with letters from each map and kept only the year. Finally, based on your suggestion, we have kept only one legend since the legends under each year are identical. Please see page 12 lines 279-383 for details.

Author Response File: Author Response.pdf