Review Reports

Round 1

Reviewer 1 Report

Dear Authors,

Although your manuscript is relevant and well-written, it has a very critical problem. You have used a non-appropriate analysis method. Use of the multivariate linear regression – the way you have handled the data with it – is only sound for continuous predictors and you have mixed them with categorical variables. I suggest that you use mixed models to solve the problem. You need to inform yourself about the topic. There is plenty of information (e.g. online lectures) which can help you. Here is a short starter tailored to your situation which may help you navigate through the topic:

Levels existing in the categorical variables are either relevant to be traced across the research process in a way that you decide to define them as fixed effects, or they are significant only to the level that they should be only accounted for in the background of the analysis process. In the first case (fixed effects) you will end up with multiple models (= one regression equation for each level of the categorical variable). Look at table 4: You probably don’t want to have distinct models to predict behavior of male and female individuals in terms of willingness to accept measures (-> Gender : Random Effect [just a mathematical correction for the behavioral similarity within gender groups is enough]) but you might need two models distinguishing regions with high-eco-tourism-potential from low-eco-tourism-potential (-> The eco-tourism affected the general situation of the region : Fixed effect)

You might also reconsider the continuous variables as well, classifying them to categories [income: e.g. three levels: Low/Middle/High or five levels: Low/Low-midlle/Middle/High-middle/high] [Income, typically – depending on its distribution in the population – needs a logarithmic transformation before being used in a regression]. Once converted to categories you do not face the problem anymore.

If doing so (converting continuous variables to categorical) you end up with only-categorical data, you have to use Generalized Linear Mixed Models for your analysis.

The two “importance level” variables in table 4 have a range which, although categorical, may be handled as continuous (excused, depending on the distribution and structure of the variable in the population). Not only to assist your decisions, but also for the sake of your readers, you need to communicate the data structure using scatter plots and histograms. If you want to keep the text short and neat you may put them in the supplementary materials.

Use the logic above and rethink the way you handled the data.

You need to check for multicollinearity among your predictors as well. Some might be possible to set aside because the information they contain is already there (in another highly correlated variable).

Although scatterplots and histograms are missing in your manuscript, it seems to me that you have collected high quality data which deserves to be analyzed properly in order to yield meaningful outputs. This is the reason I am not rejecting the manuscript. Please redo the analysis.

 

Author Response

Dear reviewer, thanks for your valuable comments. These comments indicated some errors in my manuscript, besides the ambiguity surrounding the regression model.  Therefore, I will explain the model we used besides the improvements we made to eliminate any ambiguity in the manuscript regarding the model.

1. The aim of applying a regression model was to explore all explanatory factors that affected respondents’ responses for each priority based on their selected plans (table 1). The objective of this research is to estimate the economic value of the ecosystem in WA, and based on the previous meetings with the local community, only four ES were chosen as the most important ES. Therefore, each respondent was asked to select one ES for conservation, based on their priorities: first priority, second priority, and third priority. The selected plans by each respondent represent how he/ she value the ecosystem in WA.

 

2. We had mistakenly, mentioned the multivariate model in the methods section, but we had applied the multiple linear regression in the first place, and you can compare it with the model results in the manuscript with the attached file.  The multiple linear regression was applied in WTA studies by other researchers as:).

Chu et al. 2020  https://doi.org/10.1016/j.jenvman.2019.109925

Wang et al. 2019 https://doi.org/10.3390/f10080691

Xiong et al. 2019 https://doi.org/10.3390/su11216138

Bani et al. 2017 https://doi.org/10.1007/s11842-017-9364-3

Tolunay et al.  2015 https://doi.org/10.3390/su7033311

 

In these articles, researchers used a different mix of dependent variables as continuous, binary, and categorial, also explained in the” Introductory Econometrics: modern approach Jeffrey Wooldridge”.

3. Additional information was included in section (2.3.2 Data processing method) to explain the justification of applying the regression model for each priority, we seek to explore the factors for each respondent selecting each plan. In the end, we are trying to enhance the economic value of the ES in this region.

The following information was included” In this study, three regression models of the independent variables that affected the WTA of respondents of each priority were defined with multiple linear regression models. The multiple -linear regression model equation is given the Equation (1)

Y = a + bX1 + cX2 + dX3 +…ZXn+ U                           (1)

Here, Y defines the dependent variable as the WTA of each plan in each priority; X1, X2, and Xn define independent variables as socio-economic variables, the perceptions, and use of ESs; a, b, c, Z define constants, and U is the error term”

4. Refereeing to your advice, the income variable was classified into categories. please see table 4. This variable was used only in applying the multiple linear regression model for the first priority (Table 5).

The categories of the income (JOD) are 1= less than 200, 2= 201- 300, 3= 301- 400,

4= 401-500, and 5= more than 501.

5. we have carried out the correlation test for each independent variable (Priority 1, priority 2, and priority 3) and the explanatory variables in each model. According to the attached file, no correlation of more than 0.8 was found, thus, a multicollinearity problem is not found.
6. The results of the multiple linear regression models were demonstrated in a new table with a different layout, to reduce any confusion in the results. Please see table 5 page 9.
7. I have checked the Generalized Linear mixed model. For applying this model, I have to consider the dependent variable (y) for the three priorities, thus n= 3 * 296= 888 the sample size, it means aggregating the respondents, emphasizing that each respondent had the option to select one plan in each priority, each priority is independent on the other priorities. while some of them did not respond to priority 2 or priority 3. Moreover, the variables used in this type of econometric model could be continuous and categorical variables, as applied by ( Alarcon, G.G.; Fantini, A.C.; Salvador, C.H.; Farley, J. Additionality is in detail: Farmers’ choices regarding payment for ecosystem services programs in the Atlantic forest, Brazil.  Rural Stud.2017, 54, 177–186).

Reviewer 2 Report

The topic dealt with in the paper is interesting and very topical. PES are a very promising tool for guaranteeing both the quality of ecosystems and adequate remuneration for people who work in this context by guaranteeing the reproduction of the ES or who must modify their practices in order not to jeopardize the reproduction of the ES over time.

The methodological and research framework is developed in a clear and effective way but I believe it is appropriate to highlight some weaknesses that should be eliminated:

1) When using the WTA method, it is assumed that people accept the payment of a fee for renouncing the use of a resource or carrying out activities or because they have to carry out the activities according to well-defined rules that involve higher costs or lower income. In this case is not clear what are the constraints to be respected in order to be paid. I suggest to better specify this aspect with reference to table 1.

2) It is not clear what unit of measurement of the remuneration is it. Is it expressed in the national currency or In dollars or other? Furthermore, once this point has been specified, it would be important to make readers understand the incidence of the WTA with respect to the average income of the population living in the area. I ask you to introduce these information elements.

3) I do not understand why a discount rate of 15% in 5 years is introduced. I ask you to better explain its meaning also because, if the goal is the evaluation of the Net Present Value of the WTA then an annual discount rate must be introduced and not an overall rate to then make an average annual rate.

4) It is necessary to revise the numbering of the paragraphs because it is not correct.

5) I suggest reversing the order of paragraphs 3.3 and 3.2 because we introduce the WTA plan (Table 1) without having explained what the WTA is.

6) In the conclusions, the indications reported in points 1-4 should be developed more broadly also in relation to the opportunities offered by current environmental and rural policies in Jordan. Are there already tools that allow the introduction of PES? Are there specific rural development rules for PES? is it necessary for the government to make a specific law in this area? 

Author Response

Comments and Suggestions for Authors

The topic dealt with in the paper is interesting and very topical. PES are a very promising tool for guaranteeing both the quality of ecosystems and adequate remuneration for people who work in this context by guaranteeing the reproduction of the ES or who must modify their practices in order not to jeopardize the reproduction of the ES over time.

The methodological and research framework is developed in a clear and effective way but I believe it is appropriate to highlight some weaknesses that should be eliminated:

1. When using the WTA method, it is assumed that people accept the payment of a fee for renouncing the use of a resource or carrying out activities or because they have to carry out the activities according to well-defined rules that involve higher costs or lower income. In this case is not clear what are the constraints to be respected in order to be paid. I suggest to better specify this aspect with reference to table 1.

Answer: Thank you. we had added the constraints of payments, and impacts of income / higher cost of benefits related to the priorities and plans

Based on the proposed plans for each priority, the respondent is expected to apply and/ or accept specific constraints on utilizing the ES, while restoration plans are executed in the area for 5 years. Table 1 refers to the suggested limitations and constraints that are expected to be applied in case of accepting compensation for ES. Based on these constraints/ impact, respondents are assumed to handle additional costs and/or lost income

Table 1. The suggested plans and the values (JOD*) for the three priorities used to estimate the WTA.

Suggested plans	Imposed constraints	Priority 1 JOD	Priority 2 JOD	Priority 3 JOD
Plan 1: No reaction	No constains	0	0	0
Plan 2: Establish a plan to control hunting for different types of birds and animals in some areas.	Control hunting of specific types of birds and for specific periods of time in the year.	80	60	40
Plan 3: Improvement and protection of water sources (ponds, waterfalls, and springs) and the implementation of water harvesting techniques.	Limitation on the use of water sources for touristic purposes, besides preserving and maintain any water harvesting techniques established in their areas.	300	200	150
Plan 4: Rehabilitation of grazing areas, natural vegetation, rangeland management, and firewood collection.	Control the open grazing in specific areas and periods around the year. Preserving and maintain any conservation interventions for rangeland.	600	450	300
Plan 5: Enhancing eco-tourism services and activities	Effective participation in the initiatives for establishing eco-tourism projects aligned with the restoration and ecosystem management plans.	900	675	450

*JOD refers to the Jordanian Dinar. 1 JOD = $1.41 USD

2. It is not clear what unit of measurement of the remuneration is it. Is it expressed in the national currency or in dollars or other? Furthermore, once this point has been specified, it would be important to make readers understand the incidence of the WTA with respect to the average income of the population living in the area. I ask you to introduce these information elements.

Answer: Thanks for the comments. We have included the interpretations in the manuscript. The interpretations are:  

• The compensations were expressed in the national currency (JOD refers to the Jordanian Dinar. 1 JOD = $1.41 USD). This information was included in several locations in the manuscript, where the JOD was mentioned.
• This information was included in the manuscript as the following: "The values of the suggested plans were estimated based on the annual income of the population in WA. According to [27], the annual income of the family is about JOD 3600, the maximum compensation was about 25% of this income. The plans' values were designed and validated in the pre-testing phase of the WTA scenarios, besides considering the information provided by some key persons in this phase."

3. I do not understand why a discount rate of 15% in 5 years is introduced. I ask you to better explain its meaning also because, if the goal is the evaluation of the Net Present Value of the WTA then an annual discount rate must be introduced and not an overall rate to then make an average annual rate.

Answer: thanks, the required explanations were included in the manuscript as the following: 

This high discount rate implies giving high values to the restoration plans of any ecosystem, and thus, betting against the environment and future generations. The discount rate in developing countries ranges between 8 - 15%, there is an increase by 1–2 percent per year of the discount rate for environmental projects due to the high risks in such projects. Moreover, the proposed restoration project is assumed to extend 5 years and thus the aggregate discount rate for 5 years was employed.

Additional references: 

Harrison, M. Valuing the Future: The Social Discount Rate in Cost-Benefit Analysis; Productivity Comission: Melbourne, Australian, 2010

Xu, Z.M.; Cheng, G.D.; Zhang, Z.Q.; Su, Z.Y.; Loomis, J. Applying contingent valuation in China to measure the total economic value of restoring ecosystem services in Ejina region. Ecol. Econ. 2003, 44, 345–358.

4. It is necessary to revise the numbering of the paragraphs because it is not correct.

Answer. Thank you, we had corrected the numbering of section 2.3 research methods in red color.

5. I suggest reversing the order of paragraphs 3.3 and 3.2 because we introduce the WTA plan (Table 1) without having explained what the WTA is.

Answer: Thanks for your suggestion. We think it's better to keep the same sequence, as the WTA plans (Table 1) were introduced in this section as a part of the survey instrument used in data collection. Besides, this section includes the scenario mentioned in the questionnaire that explained to the respondents to select the preferred WTA plan in each priority.

6. In the conclusions, the indications reported in points 1-4 should be developed more broadly also in relation to the opportunities offered by current environmental and rural policies in Jordan. Are there already tools that allow the introduction of PES? Are there specific rural development rules for PES? is it necessary for the government to make a specific law in this area? 

Answer:

The conclusion has been developed to reflects the suggested aspects:

The residents’ gender, age, and income were among the most significant explanatory factors that affect the compensation level of WTA. Other factors contributing to the residents benefitting from the surrounding ecosystems include the existence of eco-tourism activities and their level of importance to the study area. Meanwhile, the results of this empirical research have important policy implications:

1) the government and non-governmental organizations (NGO’s) should strengthen advocacy and education of arid ecological and natural resources protection, and raise compensation funds to support restoration programs, moreover, the current biodiversity policies in Jordan and the international agreement and treaties provide windows for structuring regulations for payments for ecosystem services (PES). At least, this should start in areas classified as protected or environmentally important areas.    

2) The current land development plans and urban planning is should enhance the diversity of income sources from farming and non-farming activities with specific consideration for the arid ecosystem ; 3) Maintain and strengthen the protection and improvement of water quality and quantity as one of the important components of an arid ecosystem, besides enhancing the ecosystem resilience for climate change and rainfall variations; and 4) Follow the down-top approach and include the local community in any decisions in establishing differentiated and diversified compensation strategies and regulations. Indeed, local residents will become aware of the long-term benefits of the conservation and restoration activities, which will eventually become self-initiated.

 

Reviewer 3 Report

The paper deals with the use of contingent valuation method to value the willingness to accept (WTA) by the households from Wadi Araba with regard different ecosystem services. The structure of the work is clear and organized in integrated manner.

In the specific terms, it is suggested: 

• to review the abstract according to the structure suggested by Sustainability: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations;
• to increase the reference literature on methodologies and tools to support the economic valuation of ecosystem services (for example, but not limited to, the contribution of: Guarini, M.R., Morano, P., Sica, F. Eco-system services and integrated urban planning. A Multi-Criteria Assessment Framework for Ecosystem Urban Forestry Projects. In: Mondini, G.; Stanghellini, S.; Oppio,A.; Bottero M.; Abastante F. (editors). Values and functions for future cities, “Green Energy and Technology”, Springer. DOI: 10.1007/978-3-030-23786-8_11).  

Author Response

Comments and Suggestions for Authors

The paper deals with the use of contingent valuation method to value the willingness to accept (WTA) by the households from Wadi Araba with regard different ecosystem services. The structure of the work is clear and organized in integrated manner.

In the specific terms, it is suggested: 

1. To review the abstract according to the structure suggested by Sustainability: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations;

Answer: Thanks, for your comment. The abstract has been revised and modified according to the structure suggested by the journal.

“Abstract

In developing countries, like Jordan, climate change and population growth have prompted land-use and land-cover changes that have profoundly affected ESs, especially by poor people living in fragile ecosystems. This study aimed to analyze the attitudes towards ES among households living in Wadi Araba, a study area located in a dry ecosystem with limited natural resources, and determine the value of ES and the main socio-economic, and perceptions factors influencing households’ willingness to accept (WTA) according to the families’ priorities.  The face-to-face method was used to interview a random sample of 296 residents from the study sites, using a structured questionnaire to capture the accepted level of compensation for conservation by the local community. Also, multiple linear regression analysis was applied to determine the main socio-economic factors affecting WTA. More than 91% of the respondents were willing to accept compensation for three different conservation plans that reflect the resident’s priority. For the three priorities, the weighted average of the compensation levels was JOD 436, 339, 261 per household per year, respectively, and the aggregate values were about JOD (1,196,977.8, 930,601.2, and 719,411.8, respectively) (JOD 1= $ 1.40). The residents’ gender, age, and income were among the most important factors that affect the compensation level. The main policy implications are that the government and non-governmental organizations should strengthen advocacy and education of arid ecological and natural resources protection, besides including the local community in any decisions in establishing differentiated compensation strategies and regulations. Eventually, the conservation and restoration activities will become self-initiated. “

 

1. To increase the reference literature on methodologies and tools to support the economic valuation of ecosystem services (for example, but not limited to, the contribution of: Guarini, M.R., Morano, P., Sica, F. Eco-system services and integrated urban planning. A Multi-Criteria Assessment Framework for Ecosystem Urban Forestry Projects. In: Mondini, G.; Stanghellini, S.; Oppio,A.; Bottero M.; Abastante F. (editors). Values and functions for future cities, “Green Energy and Technology”, Springer. DOI: 10.1007/978-3-030-23786-8_11).  

Answer:

• Thank you. We had included this reference in the discussion section, final paragraph. “Such decisions should be devoted to considering different constraints, measures of decision and outcome effectiveness, and multi-criteria decision-making for integrating ecosystem sustainability in urban planning [61].”

 

Round 2

Reviewer 1 Report

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