The Volatility Dynamics of Prices in the European Power Markets during the COVID-19 Pandemic Period
, Milena Nebojsa Rajic 1, Zorana Božić 2, Peđa Milosavljević 1, Ancuța Păcurar 3, Cristina Borzan 3, Răzvan Păcurar 3 and Emilia Sabău 3,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsPlease refer to the attached document for my comments and suggestions. I urge the authors to incorporate them in detail to improve the overall quality of their analysis and exposition.
Comments for author File: 
Comments.pdf
English is ok, but the authors need to stick with a single (consistent) writing style instead of swaying between passive/active voices, verbal persons, etc.
Author Response
Dear Reviewer,
Thank You for Your valuable comments. We have provided the answers to your remarks in attached document.
With respect,
Authors
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe submitted manuscript addresses the power market price volatility issue during COVID-19 pandemic on the European power markets. The study analyzes quantitatively the power prices in the time frame between 1.1.2018 and 12.12.2021 for 28 European countries, the individual power exchanges. The central shortcoming of the paper is the incongruence of the abstract. The author states that volatility is the central focus of the paper. But, states that increased prices during the pandemic is the central finding. The author has to fix this. The main problem of the manuscript are the figures and diagrams. None of them is really in line with standards. Figures 1 and 2 are really of low quality and low resolution. Tables 1 and 2 are too extensive for the main text part and hence, belong to appendices. The authors use a simple statistical method for the assessment of volatility. This is fine. But at least refer to the confinement of such an approach. Refer also to nonlinear methods such s NARDL. Refer to applied studies such as https://doi.org/10.1017/jwe.2021.32 Furthermore, there are some inconsistencies in the references list. Some cited sources are not in the list.
Comments on the Quality of English LanguageEnglish is fine
Author Response
Dear Reviewer,
Thank You for Your valuable comments. We have provided the answers to your remarks in attached document.
With respect,
Authors
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsIn this paper, authors explored the power price volatility from 2018 to 2021 on twenty-eight power exchanges in Europe from several aspects including daily, monthly, quarterly and annual levels. Experimental results were obtained and analyzed with further suggestions on energy policy provided finally. Overall, this paper is with sufficient research content and suits Sustainability. But the contributions to the existing studies are unclear and should be further highlighted. By the way, some issues are raised as follows from two aspects:
1. Major issues.
(1.1) Some key findings from the experiments should be added to the Abstract part to emphasized the importance and strictness of this study.
(1.2) Section 2 summarized the related work from literature. However, the structure is not well-organized and the research gap is unclear. As known to all, there are many studies on electricity market analysis or policy formulation, what is authors’ contribution?
(1.3) Serious flaws exist in Section 3 Materials and Methods. Firstly, authors introduced several methods by citing relevant literature. For example, DVOA, DVDA, DVQA, DVYA, fixed base index and chain base index. Which method or a combination of several of them was used by authors in this article? These methods are relatively mature and the contribution is unclear. Secondly, as authors stated in Abstract, the data were analyzed from daily, monthly, annual levels. Are the methods used for these levels the same and effective? Thirdly, some parameters were presented in Equations, but they are not clearly introduced. Potential readers may wonder the meaning behind these parameters.
(1.4) Section 4 reported related results and discussions. Some issues are found. Firstly, Fig .1 lacked an explanation of the horizontal and vertical coordinates. Secondly, authors analyzed the price data from daily, monthly, quarterly and annual levels. Further descriptions on them should be given. Why these four levels are required for power price analysis and what additional conclusions can be drawn by comparing with single level? The reviewer supposes it is a good chance to present the contributions and differences subject to existing studies.
2. Minor issues.
(2.1) The value range of i does not need to be expressed in Eq. (3).
(2.2) Fig. 2 is too vague to be distinguished.
(2.3) Two L1 in Table 1.
(2.4) Equation S=G-100 in Table 1 should be revised to match the data.
(2.5) Line 219, ‘the second hypothesis’ is advised to be expressed as ‘H2’.
(2.6) Line 244, ‘the first hypothesis’ is advised to be expressed as ‘H1’.
(2.7) Line 263, ‘the third hypothesis’ is advised to be expressed as ‘H3’.
(2.8) Future search directions or next actions can be added to Section 5 to extend the scope.
(2.9) According to the iThenticate report, Percent match is 29%, which is high.
Author Response
Dear Reviewer,
Thank You for Your valuable comments. We have provided the answers to your remarks in attached document.
With respect,
Authors
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper has been improved and could be published now.
Comments on the Quality of English LanguageThe paper has been improved and could be published now.
Reviewer 3 Report
Comments and Suggestions for AuthorsMy raised comments are well addressed by authors.
