Willingness to Pay for Geothermal Power: A Contingent Valuation Study in Taiwan

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Sir, 

Many tanks for your invitation to review this paper.
Based on the review of the paper titled "Willingness to Pay for Geothermal Power: A Contingent Valuation Study in Taiwan" which submitted to the Energies Journal.
After review of this paper, we think that this paper is suitable for publication in this Journal.
This paper is very good structured. 
The subject of this paper is very important
The introduction needs to be improved by presenting the motivations and the objectives and the paper structure.
The references needs to will be improved by added recents (2024 and 2025)
The paper needs political and managerial implications.

I think that this paper is suitable for publication in the Energies Journal after that the authors complete all needed revisions.

All the best 

Author Response

Comments 1: [After review of this paper, we think that this paper is suitable for publication in this Journal. This paper is very good structured. The subject of this paper is very important]

Response 1: [We sincerely thank you for your time, effort, and very positive assessment of our manuscript. We are pleased to hear that the reviewer found the structure to be good and the subject matter to be important and suitable for publication in the journal.]

 

Comments 2: [The introduction needs to be improved by presenting the motivations and the objectives and the paper structure.]

Response 2: Agree. Revised the introduction (Page 1, lines 11-21) to explicitly state the motivation and research objective. A rewritten paragraph was updated to clearly outline the paper structure, making the flow immediate and clear.

 

Comments 3: [The references needs to will be improved by added recents (2024 and 2025)]

Response 3: Agree. Updated the citations to include some recent and necessary references (2024 and 2025). These recent works were strategically integrated into the Literature Review and Discussion (e.g., Page 6, lines 231-235; Page 22, lines 716-719), addressing the need for recency.

 

Comments 4: [The paper needs political and managerial implications.]

Response 4: Agree. Added paragraphs discuss about "political and managerial implications" within the Discussion (Page 21-22, lines 701-732). Clearly providing both Political and Managerial Implications stemming from our findings, as requested.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This article examines willingness to pay for geothermal energy using Taiwan as a case study, demonstrating certain research value. However, improvements are recommended in the following areas:

1. Abstract section. The abstract should primarily encompass research background + methodology + conclusions + significance. Yet the current abstract appears rather disjointed; it is advisable to restructure it.

2. Literature review section. This section lacks a synthesised overview of the literature. It is recommended to either add a dedicated section or convert section 2.5 into a summary, emphasising the marginal contribution of this study or outlining the specific aspects explored in comparison to previous literature.

3. Section 4: Questionnaire Design and Data Collection. While the study population is specified as residents of Taiwan, it is advisable to provide detailed sample characteristics such as gender distribution and age groups. Such specifications enhance the scientific rigour and accuracy of the conclusions.

4. Table 7 omits the coefficient of determination (R-squared). Might this be added?

5. Conclusions. It is recommended to include a discussion of the study's limitations.

Author Response

Comments 1: [Abstract section. The abstract should primarily encompass research background + methodology + conclusions + significance. Yet the current abstract appears rather disjointed; it is advisable to restructure it.]

Response 1: Agree. The Abstract (Page 1, lines 11-31) has been restructured to ensure it clearly covers the background, methodology, main findings, and significance in a cohesive manner.

 

Comments 2: [2. Literature review section. This section lacks a synthesised overview of the literature. It is recommended to either add a dedicated section or convert section 2.5 into a summary, emphasising the marginal contribution of this study or outlining the specific aspects explored in comparison to previous literature.]

Response 2: Agree. A new, summary section has been added at the end of the Literature Review (Page 8, lines 317-345). This section synthesizes prior research and explicitly highlights the marginal contribution of our study.

 

Comments 3: [3. Section 4: Questionnaire Design and Data Collection. While the study population is specified as residents of Taiwan, it is advisable to provide detailed sample characteristics such as gender distribution and age groups. Such specifications enhance the scientific rigour and accuracy of the conclusions.]

Response 3: Agree. We have added detailed sample characteristics (Page 12-14, lines 457-500), including data on gender, age groups, and education, to enhance the scientific rigor of the conclusions.

 

Comments 4: [4. Table 7 omits the coefficient of determination (R-squared). Might this be added?]

Response 4: Agree. Table 7 (Page 19-20, lines 630, 631; new Table numbering to Table 11) has been updated to include the R-squared.

 

Comments 5: [5. Conclusions. It is recommended to include a discussion of the study's limitations.]

Response 5: Agree. The Conclusions section (Page 23-24, lines 777-808) now includes a dedicated discussion addressing the limitations of the study and suggesting directions for future research.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This study aims to quantify the public’s willingness-to-pay (WTP) more for switching from coal-fired power generation to geothermal power generation. A strength of the study is the authors’ use of the contingent valuation method (CVM), as this method is one of the few that allows for the monetization of public goods such as reduced greenhouse gas emissions.

 

Shortcomings:

1. One of the main shortcomings is the disregard of citizens’ income as a predictor of willingness-to-pay (WTP). Income is one of the main predictors of the population’s willingness to pay for public goods (e.g., reducing greenhouse gas emissions). The omission of the variable “income” from the model (equation 6) raises questions about the reliability of the estimated effects of other variables.
2. The authors excluded 381 protest responses, or one in three questionnaires. Such a high percentage (35.67%) of surveys excluded from the analysis creates a distorted picture of public opinion. This biases the sample toward those who are willing to pay for the energy transition out of their own pockets, while ignoring the opinions of respondents who believe the state or the business sector should finance the energy transition.
3. An analysis of the questionnaire’s structure (Appendix A) reveals a serious problem (the framing effect). For example, before the question about the respondent’s willingness-to-pay for the transition from coal-fired power generation to geothermal power generation, the questionnaire includes information about effectively promoting geothermal energy, describing its advantages.

 

1^st Recommendation: To add the variable “income” to equation 6 in paragraph “5. Empirical results” and recalculate the empirical results obtained and presented in “Table 6. Descriptive Statistics of the Explanatory Variables” and “Table 7. Model Estimation Results for Single-Bounded Dichotomous Choice Elicitation Models.” The authors collected data about respondents’ incomes (Section IV, Question 7), so recalculation is possible without conducting additional surveys.

2^nd Recommendation: After elaborating a new regression model that includes the variable “income”, it is necessary to conduct and present the results of several tests, including a multicollinearity test.

3^rd Recommendation: The presence of such a high percentage of “protest responses” is one of the key findings of this study, so it is necessary to add a paragraph in which the 381 questionnaires that the authors classified as “protest responses” should be analyzed. This analysis will help understand the barriers to the adoption of energy transition financing mechanisms and identify preferred financing models for society.

Author Response

Comments 1: [One of the main shortcomings is the disregard of citizens’ income as a predictor of willingness-to-pay (WTP). Income is one of the main predictors of the population’s willingness to pay for public goods (e.g., reducing greenhouse gas emissions). The omission of the variable “income” from the model (equation 6) raises questions about the reliability of the estimated effects of other variables.]

Response 1: Agree. Recalculation Performed: The empirical analysis was performed again using the original collected data. Income Variable Added: The "income" variable has been successfully incorporated into the WTP model (Equation 6). Data Handling: The categorical nature of the original income data was carefully processed and integrated into the new regression model. Significance Discussed: The significance of the new income variable and its impact on the significance of other variables is thoroughly discussed in the newly revised section. WTP Impact: The calculated Willingness-to-Pay (WTP) increased slightly, by approximately 1 USD, following the inclusion of income. Overall Model Stability: The overall results and the estimated effects of the other explanatory variables remain largely consistent, confirming the robustness of the initial findings. Multicollinearity Test: A VIF multicollinearity test was conducted on the revised model, and the results confirmed that no problematic multicollinearity exists. Update Scope:Page16-20, lines: 565-567, 580-582, 619-643

 

Comments 2: [The authors excluded 381 protest responses, or one in three questionnaires. Such a high percentage (35.67%) of surveys excluded from the analysis creates a distorted picture of public opinion. This biases the sample toward those who are willing to pay for the energy transition out of their own pockets, while ignoring the opinions of respondents who believe the state or the business sector should finance the energy transition.]

Response 2: Agree. Protest Analysis Added: Analysis of the 390 "protest responses" is now included. Data Corrected: The protest sample size was fixed from 381 to 390. The total WTP analysis sample (678) was confirmed as correct. Document Updated: Page12-16, lines: 455-553

 

Comments 3: [An analysis of the questionnaire’s structure (Appendix A) reveals a serious problem (the framing effect). For example, before the question about the respondent’s willingness-to-pay for the transition from coal-fired power generation to geothermal power generation, the questionnaire includes information about effectively promoting geothermal energy, describing its advantages.]

Response 3: Agree. Limitation Discussion Added: A new discussion section addressing the framing effect has been added to the limitations of the study. This section specifically addresses how the preceding informational text on the advantages of geothermal energy, placed before the WTP question, may have influenced respondents' answers. Document Update Scope: The detailed discussion of this limitation is located in the following area: Page23-24, lines: 786-790

 

Comments 4: [1st Recommendation: To add the variable “income” to equation 6 in paragraph “5. Empirical results” and recalculate the empirical results obtained and presented in “Table 6. Descriptive Statistics of the Explanatory Variables” and “Table 7. Model Estimation Results for Single-Bounded Dichotomous Choice Elicitation Models.” The authors collected data about respondents’ incomes (Section IV, Question 7), so recalculation is possible without conducting additional surveys.]

Response 4: Agree. Recalculation Performed: The empirical results have been recalculated by incorporating the "income" variable into Equation 6 using the original collected data (Section IV, Question 7). WTP Impact: The new estimation shows that the calculated Willingness to Pay (WTP) has increased by approximately 1 USD. Variable Stability: The results confirm that the significance and direction of the other explanatory variables remain fundamentally consistent with the previous model. Document Updates: The revised empirical results, including the updated descriptive statistics and model estimation tables, have been implemented across the document in the following scope: Page16-20, lines: 565-567, 580-582, 619-643

 

Comments 5: [2nd Recommendation: After elaborating a new regression model that includes the variable “income”, it is necessary to conduct and present the results of several tests, including a multicollinearity test.]

Response 5: Agree. VIF Multicollinearity Test Conducted: A Variance Inflation Factor (VIF) test was performed on the new regression model that includes the "income" variable. No Multicollinearity Detected: The results of the VIF test confirm that no problematic multicollinearity exists among the independent variables in the new model. Document Update Scope: This confirmation and the relevant VIF results have been added to the document in the following area: Page 20, line 643 Page20, lines: 643

 

Comments 6: [3rd Recommendation: The presence of such a high percentage of "protest responses" is one of the key findings of this study, so it is necessary to add a paragraph in which the 381 questionnaires that the authors classified as "protest responses" should be analyzed. This analysis will help understand the barriers to the adoption of energy transition financing mechanisms and identify preferred financing models for society.]

Response 6: Agree. Protest Analysis Added: Analysis of the 390 "protest responses" is now included. Data Corrected: The protest sample size was fixed from 381 to 390. The total WTP analysis sample (678) was confirmed as correct. Document Updated: Revisions are complete in the specified lines on Page16-20, lines: 565-567, 580-582, 619-643

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors did a great job:

• The authors have added the variable “income” to equation 6. The significance of the newly introduced variable (income) and its impact on the significance of other variables are discussed in detail in the newly revised section.
• A VIF multicollinearity test was conducted on the revised model, and the results confirmed that there is no problematic multicollinearity.
• The analysis of the 390 “protest responses” was included.
• A new discussion section addressing the framing effect has been added to the limitations of the study.

Comments for author File: Comments.docx

Author Response

Dear Reviewer,

Thank you very much for your thoughtful and constructive comments on our manuscript. We sincerely appreciate the time and effort you have dedicated to reviewing our work.

In the previous revision round, we carefully addressed all the points you suggested:

• We added the variable income to Equation (6) and thoroughly discussed its significance as well as its influence on the significance of other variables within the revised section.
• We conducted a VIF multicollinearity test for the updated model, and the results confirmed that no problematic multicollinearity exists.
• We incorporated the analysis of the 390 protest responses into the manuscript.
• We added a new discussion section in the limitations addressing the framing effect.

In this round of review, no additional revisions were required. Nevertheless, we would like to express our sincere gratitude for your previous guidance, which significantly improved the clarity and robustness of our manuscript. Your insightful feedback has been invaluable in helping us strengthen the study.

Thank you again for your time, expertise, and support.

Sincerely,
Wei-Chun Tseng , Tsung-Ling Hwang
Department of Applied Economics National Chung-Hsing University, Taiwan