Long-Term Network Structure Evolution Investigation for Sustainability Improvement: An Empirical Analysis on Global Top Full-Service Carriers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please find the comments in the file.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presents a long-term network structure evolution for ten big airlines. It does not propose any new method; instead, it focuses on data analysis. Such a thorough report and the conclusions drawn can be helpful when planning new network upgrades. There are, however, some points that should be improved. 

– Since the main point of this study is a wide data analysis, the manuscript should indicate the data sources and data structure. 

– There are some instances where the manuscript relies too much on references, failing to include necessary information. E.g., Section 3.1 introduces triads, dividing them into categories (line 174) and only noting the categories by name. There should be at least a sentence of explanation about the details of each category before referring the reader to an external paper. Another example would be the ACF analysis in Section 4.6: there are four states of ACF without any explanation of what they mean, only referencing an external work. They should be explained in at least a sentence to keep integrity and self-continence. 

– The presentation should be improved, especially:

(a) in Table 5 the acronyms should be explained in the table caption and not in the note below the table, to improve readability, 

(b) Figure 4 is not explained enough – the manuscript states in line 359 that it was "drawn by network drawing software" but fails to explain more details on what is actually presented, 

(c) Figures 3, 5 and 6 should be bar plots instead of line plots. The lines connect different airlines when there is no relationship between them. I would suggest using a series of triads of bars (three bars (2011, 2015, 2019) for each airline) instead of connected points, to easily show the changes over time within each airline. 

– The manuscript should be carefully checked for typos, clarity and unnecessary fragments (e.g., the first four lines of Section 4 seem to be some leftover review). 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I would like to thank the authors for making the effort to improve the paper. All my doubts have been addressed in the revised manuscript version and in the author response, I have no further comments.