Analysis of the Water-Energy Coupling Efficiency in China: Based on the Three-Stage SBM-DEA Model with Undesirable Outputs

Round 1

Reviewer 1 Report

This article used a three-stage Slacks-Based Measure model for Data Envelopment Analysis (SBM–DEA) to estimate the water–energy coupling efficiency in China from 2003–2015.  They Used the Stochastic Frontier Approach (SFA) regression model to constructe an index of environmental factors that affect the water–energy coupling efficiency from the four aspects of resource environment, social environment, economic environment, and ecological environment. This article finishes a useful job of homework of DEA technique and SBM in general. Thus, this article does propose enough novel information in the application development of data envelopment analysis (DEA).  Thus, there are enough practical contribution exist in this manuscript.  We suggest that author can further explain the analytical mechanism in the DEA method in order to highlight the methodology contribution of the work.  The empirical results can provide enough solid/valid bases to judge the pros and cons of the DEA method in the performance evaluation. However, the impact on the management implications and the empirical results comparison to the other related literature are neglected in the conclusion section of the manuscript; the rationale of this missing issue is required to fully explanation in this section, with the interesting issue of business investment or outsourcing decision, and so on. Thus, the reviewer is convinced from the evidences arise from the author, thus, the reviewer can suggest to recommend the publication this paper in the slighted revised version. 

Author Response

Response to Reviewer 1 Comments

Dear reviewer

Hello,

   Thank you for reading my manuscript during your busy schedule and presenting valuable review comments. We have learned much from your comments, which are fair, encouraging and constructive. After carefully studying the comments and your advice, we have made corresponding changes. Our response of the comments is enclosed at the end of this letter.  We also add some experiments in this manuscript.  If you have any question about this paper, please don’t hesitate to contact us.

 

 

 

Point: We suggest that author can further explain the analytical mechanism in the DEA method in order to highlight the methodology contribution of the work. The empirical results can provide enough solid/valid bases to judge the pros and cons of the DEA method in the performance evaluation. However, the impact on the management implications and the empirical results comparison to the other related literature are neglected in the conclusion section of the manuscript; the rationale of this missing issue is required to fully explanation in this section, with the interesting issue of business investment or outsourcing decision, and so on.

 

Response:

Thanks for your comments, this article adds a corresponding explanation about the analytical mechanism in the DEA method. We do lack support for the corresponding explanation in this paper, especially in the conclusion. We add the explanation about the analytical mechanism.

At the same time, in the conclusion section, this paper adds the impact on the management implications. And, in the follow-up to the impact, we add a supplement of the current situation of the management efficiency about the coupling level of water and energy in China in an attempt to adapt its research to the literature. As for the empirical results comparison to the other related literature which are neglected in the conclusion section, we need to explain that there are few high-quality literature using the three-stage DEA model to study the coupling efficiency of water and energy. Thus, in the conclusion section, we add the literature of calculating efficiency by traditional DEA method, and highlight the superiority of three-stage DEA by the comparison of the both methods. Such as follows:

 

The traditional DEA model does not take into account the influences of environmental factors and random noise on the efficiency evaluation of the DMU [25]. And it is necessary to isolate these factors through SFA regression model to construct an index an index of environmental factors that affect the water–energy coupling efficiency from the four aspects of resource environment, social environment, economic environment, and ecological environment. In the second stage, the external environmental factors and stochastic factors are further removed, which results in DMU input redundancy by only management inefficiency [34]. After removing the external environmental factors and stochastic factors, this paper measured the efficiency of each DMU again, the efficiency of the stage three just reflects efficiency under the current management implications. This method can overcome the decision bias caused by the radial and angled DEA, and can also eliminate the influence of external environment and stochastic factors on efficiency evaluation. The empirical results can provide enough valid bases to judge the pros and cons of the DEA method in the performance evaluation. The results of the study are as follows.

(1) In the first stage, we used the SBM model to determine that the water–energy coupling efficiency in China was relatively high and stable, with a spatial ranking from northeast> east> west> central. However, after rejecting the influences of external environment and random factors and using the SBM model again, we determined that the efficiency values of each region declined to different degrees over time and that the efficiency values in the north-east declined more sharply year by year. The comparison results showed that the management policy of the coupling level of water and energy in China is not comprehensive enough and improving the management level would be an effective way to improve the water–energy coupling efficiency. The coupling efficiency of water and energy in China currently depends on a favorable external environment, and China’s management level of technological and institutional innovation still has some space for improvement.

(2) After the SFA regression in the second stage, it was showed that the resource environment and social environment had significant positive impacts on all inputs. In the meantime, the increase in the proportion of the economic and ecological environments was not conducive to narrowing the gap between all inputs and the ideal inputs, but the increase of the proportion of the economic environment was helpful for reducing the slack of energy consumption and the ecological environment had a positive impact on water footprint investment.

 

 

I would like to thank you for reviewing this article and providing valuable comments during your busy schedule. This provides important ideas for the revision and deep analysis of this article. This article continues this idea and has been modified accordingly. At the same time, after reading the teacher's review comments carefully, we deeply felt the shortcomings in our article. Thank you again for your contribution to this article.

Sincerely yours,

Meng Wang

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper is well written, novel, and very interesting. 

-The symbol for "rho" in equation one is not the same as the one identified in line 157.  Shouldn't it be the same symbol?

-Should the K*T in lines 157 and 160 be capitalized, or not?  Should they be the same?

-Figure 2 - the font in this figure needs to match the font in the rest of the manuscript.

-At the bottom of equation (2), the range of values for n, m, and i should have a series of periods to reflect the missing intermediate values, not as you have it depicted.

-To be consistent, the legends in figures 1 and 3 should be arranged by color in the same way.  As they are now, figure 1 is more aesthetically pleasing.

The methodology and results of this study appear to be sound and I recommend no changes or additions.

Author Response

Response to Reviewer 2 Comments

Dear reviewer

Hello,

   Thank you for reading my manuscript during your busy schedule and presenting valuable review comments. We have learned much from your comments, which are fair, encouraging and constructive. After carefully studying the comments and your advice, we have made corresponding changes. Our response of the comments is enclosed at the end of this letter.  We also add some experiments in this manuscript.  If you have any question about this paper, please don’t hesitate to contact us.

 

 

 

Point 1: The symbol for "rho" in equation one is not the same as the one identified in line 157.  Shouldn't it be the same symbol?

 

Response 1: Thanks for your correction, we really did not find this problem before, and we have now corrected the problem accordingly in line 160.

 

 

 

Point 2: Should the K*T in lines 157 and 160 be capitalized, or not?  Should they be the same?

 

Response 2: Thank you for your advice again. Here, in line 157 of the original text, the K*T represents the amount about a total value of all DMUs, but at the same time k*t represents the specific data for unit k*t, which we do not consider K*T and k*t to be the same concept and which was not caused by our negligence.

 

 

 

Point 3 and 4:

Figure 2 - the font in this figure needs to match the font in the rest of the manuscript.

At the bottom of equation (2), the range of values for n, m, and i should have a series of periods to reflect the missing intermediate values, not as you have it depicted.

 

Response 3 and 4: Thanks for the comments of the reviewer! We careless for it, thank you for pointing out and the corresponding changes have been made.

 

 

 

Point 5: To be consistent, the legends in figures 1 and 3 should be arranged by color in the same way. As they are now, figure 1 is more aesthetically pleasing.

 

Response 5: Thank you very much for your valuable advice. We've made a corresponding correction. And we also make some other changes in figure 1 and 2 to make it more intuitive and clear.

 

 

 

I would like to thank you for reviewing this article and providing valuable comments during your busy schedule. This provides important ideas for the revision and deep analysis of this article. This article continues this idea and has been modified accordingly. At the same time, after reading the teacher's review comments carefully, we deeply felt the shortcomings in our article. Thank you again for your contribution to this article.

Sincerely yours,

Meng Wang

 

Author Response File: Author Response.pdf