Determinants of Residents’ Willingness to Pay for Water Quality Improvements in Haikou, China: Application of CVM and ISM Approaches

Round 1

Reviewer 1 Report

The paper has potential and it can be a good contribution to the literature. The authors applied the double-boundary dichotomous contingent valuation method (CVM) to obtain residents' WTP for water quality improvements, calculate the average annual willingness of Haikou residents to pay for water quality improvements, and explore the determinant factors influencing residents' WTP for water quality improvements. Nevertheless, some aspects need to be changed or better explained before being considered for publication, for example:

·       The abstract could be improved, for example including more achievements;

·       Highlight the novelty of this study in the introduction;

·       Literature review can be improved;

·       It can be improved, for example emphasizing the diverse aspects that are related to willingness to pay (Marque et al., 2016);

·       All the abbreviations must be presented in the text;

·       Regarding the methodology, the model must be better justified, including the limitations;

·       The region can be an important factor that influence the results?

·       The authors could improve the discussion providing more insights about the future with this approach;

·       The units of the variables presented in the tables should include the unit;

·       Moreover, try to explain better the definition of the variables and the source of data;

·       Water quality service is important and several approaches can be adopted (see PINTO et al., 2017);

·       Explain better the statistical significance of the variables and its meaning;

·       The limitations of the study and future research can be highlighted in the conclusions;

·       More recommendations for the decision makers were expected in the conclusions;

·       The references must be homogenized and in line with the author guidelines (for example, some issues are missing).

References:

MARQUES, R.; CARVALHO, P.; PIRES, J.; FONTAINHAS, A. (2016). Willingness to pay for the water supply service in Cape Verde–how far can it go. Water Science and Technology: Water Supply. IWA. ISSN: 1606-9749. Vol. 16, no. 6, pp 1721-1734.

PINTO, F. S.; SIMÕES, P.; MARQUES, R. (2017). Water services performance: Do operational environment and quality factors count? Urban Water Journal. Taylor & Francis. ISSN: 1573-062X .  Vol. 14, no.8, pp. 78-781.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This paper explored the determinant factors influencing residents' WTP for water quality improvements, I noticed some critical problems and please go through each point carefully and revise the manuscript.

1. In the introduction section, add some recent literature, such as around 2020.

2. The novelty and main contributions of the paper should be highlighted in the introduction part, which is not prominent in the current paper.

3. The empirical analysis of influencing factors should not only report the significance of each factor, but also explain the reasons as much as possible.

4. In the ISM analysis part, the author proposed two paths, but how these two paths specifically influence the WTP of the respondent?

5. In the discussion section, it is better to add more literature and compare it with existing research conclusions.

There are also some details problems: 

① Method : is it should be double-bounded contingent valuation method (CVM)?

② In table 2, variable definition, gender of household head, age of household head，

③ Language needs to be further refined in the full text.

④ Line 289， 75 dollars or RMB?

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The framework of this manuscript has promising results however some changes are required. Please find my comments below:

*Please use the reference style as stated in the Author Guidelines

*Lines 33-36: need reference and should be included in the reference list below.

*Line 52: replace “WTP” by “willingness to pay (WTP)” because it appeared for the first time in the introduction section. Do the same for CVM in line 54.

*Lines 56-57: “CVM is particularly popular due to its versatility and immediate feedback (Fox et al., 1998).” Please use a recent reference.

*Line 66: I could not find “Todd et al.” in the reference list.

*Line 69: “the importance of the environment”, I do not understand, what do you mean?

*Please follow what you have mentioned in lines 99-102. Section 3 supposed to be “Results and Discussions” and section 4 supposed to be “Conclusions”. And then you can add section 5 and name it “Policy Implications”.

*Please rename section 2 “Materials and Methods”

*Line 109: respondents' maximum WTA (WTP), correct it: respondents' maximum willingness to accept (WTA)

*Line 110: willingness to accept (WTA), use abbreviation WTA

*Lines 113-118: need reference

*Lines 202-211: please provide reference for all data mentioned in this paragraph.

*Lines 215-216: I could not understand how Figure 2 refers to varying levels of water body pollution?

*Lines 217-220 & lines 22-224 & line 272: need reference

*Lines 246-254: move to Section 3 “Results and Discussions”

*Section 2.5 includes many data that can be part of Section 3 “Results and Discussions”

*Table 3, please make sure to use only English Language

*Table 5 came before Table 4?

*Conclusion section must be rewritten. There are a basic steps for writing a conclusion. Conclusion for your research paper must be written in this way: (1) Restate your research topic, (2) Restate the thesis, (3) Summarize the main points, (4) State the significance or results, and (5) Conclude your thoughts. You can keep the limitation paragraph (lines 423- 435) at the end of the conclusion section.

*Lines 436-450: put it under new section under the name “Policy Implications” as I mentioned earlier.

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

The paper does a good job of discussing the issue, and provides substantial statistical evidence on WTP for water quality. Regarding the paper's methodology, the paper easily meets standards for economic research.

I have two reservations about the paper. One is the applicability of survey results. People often do not know their actual preferences for WTP, so while the paper does a good job of analyzing the data, the underlying data are subject to question. I am unsure that the survey responses represent actual willingness to pay.

The survey respondents were provided with information about  water quality prior to answering the WTP survey questions, and there is a good chance that respondents were guided by that information. If respondents were informed that water quality is already good, they would answer with low WTP for improvements. If they were informed about water quality problems, they might respond with a higher WTP. My point is that the survey responses were likely heavily influenced by what the respondents were told prior to taking the survey. They may have been repeating back what they were told prior to taking the survey.

A second issue is that respondents surely were more informed than the general population. That raises the question of whether policy should be based on informed survey respondents (and possibly misinformed survey respondents!) or the views of the general population. If respondents were informed about water quality problems, they might have a higher WTP than the general population, who views water quality as acceptable without being more informed. Should public policy be based on the expressed preferences of an informed few, or by the preferences of the population as a whole?

Author Response

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Reviewer 5 Report

This paper uses CVM to calculate the average annual willingness to pay for water quality improvements among Haikou residents and explores the determinants that influence residents' WTP for water quality improvements. For problems with the article, it is suggested that it be revised for publication.

1.      The formatting of the tables needs to be modified to maintain aesthetics. For example, the contents of Table 2 should not be serial and the contents of Table 3 also contain Chinese

2.      The quality of the diagrams also needs attention, the words in Figure 3 overlap and it is difficult to read the content.

3.      Please change references to the format recommended by mdpi.

4.      Has the practice of residents paying separately for water purification been implemented in some areas? Did it work out? What is the will of the public? Please add to the introduction.

5.      Which software was used to implement the CVM and ISM methods used in the article? Please add a relevant description in the Materials and Methods section.

6.      The structure of the article is more problematic, with Section 4, Conclusions and Discussion, being more of a conclusion and outlook. The analysis of the data results in Section 3 Results, does not go far enough and should be explored in depth in relation to local and national policies.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Dear Authors,

Thanks for addressing my comments, but I still could not find the reference "Todd et al.” in the reference list. The one you included in lines 591-592 does not have the same author name.

 I also suggest to add the main results to the conclusions section.

Please also move the "Policy Implications" to be before the "conclusions" section.

Author Response

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Author Response File: Author Response.pdf

Reviewer 5 Report

Thank you for your careful response to the comments.

Author Response

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Author Response File: Author Response.pdf