1) DATABASES

We propose here two databases:

1.1) 2017_WTP_LITERATURE_DATABASE

This database describes the variables used to build the benefit transfer function. We built this database using Amuakwa-Mensah database and the USGS Benefit Transfer Toolkit, and by consolidating these databases with a literature review. The CSV file contains all the variables required to build the benefit transfer function using the R code below (parameters are set as dummy variables).

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## CHOOSE DIRECTORY
setwd("~/CHOOSE DIRECTORY")
#PACKAGES
library(Hmisc)
library(corrplot)
#1_BENEFIT TRANSFER FUNCTION BUILDING
WTP_database<-read.table("2017_WTP_LITERATURE_DATABASE.txt",h=T) ##database loading
linearMod <- lm(ln_WTP ~ ToC_No_dim + Local_Stat_No+ SurvTyp_face2face + SurvTyp_Internet + SurvTyp_Mix + SurvTyp_Phone + ln_GDP_PPP + ValuationMethod_CE + ValuationMethod_Hybrid + mod_Trustfund + mod_bill + mod_Unspecified + mod_Membership + Freq_Monthly + Freq_Once + Freq_Unspec + Units_perPerson + Class_bird + Class_MarinFish + Class_Freshwaterfish + Class_freshwaterMammal + Class_MarineRiv_fish + Class_MarineReptile + Class_TerrestrialMammal + ln_Mean_Lenght + ln_Mean_Weight,data=WTP_database)  # build linear regression model on database
print(linearMod)
summary(linearMod)

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Field of the CSV file :

Reference : source of the information

Location : Location of the study

SiteName : Location of the study (more detailed)

PrimarySpecies : Studied species

TypeofChange_mod : Type of change in the conservation status aimed

ToC_No_dim : Type of change in the conservation status aimed (dummy : increase (ref) vs. no depletion)

Local_Stat : Local Endangerement status

Local_Stat_No: Local Endangerement status (dummy: endangered (ref) vs. not endangered)

SurvTyp: Type of survey

SurvTyp_face2face: Type of survey (dummy: mail (ref) vs. face2face vs. internet vs. mixed vs. phone)

SurvTyp_Internet: Type of survey (dummy: mail (ref) vs. face2face vs. internet vs. mixed vs. phone)

SurvTyp_Mix: Type of survey (dummy: mail (ref) vs. face2face vs. internet vs. mixed vs. phone)

SurvTyp_Phone: Type of survey (dummy: mail (ref) vs. face2face vs. internet vs. mixed vs. phone)

GDP_PPP: Country GDP-PPP at the time of the study

ln_GDP_PPP: Logarithm of the country GDP-PPP at the time of the study

YearDataWereCollected: Year of the data collection

SampleFrame_mod: Sample frame as the type of respondent

SampleFrame_vis: Sample frame as the type of respondent (dummy: resident (ref) vs. visitor)

ValuationMethod: Valuation Method

ValuationMethod_CE: Valuation Method (dummy: CMV (ref) vs. CE vs. hybrid)

ValuationMethod_Hybrid: Valuation Method (dummy: CMV (ref) vs. CE vs. hybrid)

Way_mod: Way of payment

mod_Trustfund: Way of payment (dummy: tax (ref) vs. bill vs. unspecified vs. membership)

mod_bill: Way of payment (dummy: tax (ref) vs. bill vs. unspecified vs. membership)

mod_Unspecified: Way of payment (dummy: tax (ref) vs. bill vs. unspecified vs. membership)

mod_Membership: Way of payment (dummy: tax (ref) vs. bill vs. unspecified vs. membership)

Freq_mod: Frequency of payment

Freq_Monthly: Frequency of payment (dummy: annual (ref) vs. monthly vs. once vs. per visit vs. unspecified)

Freq_Once: Frequency of payment (dummy: annual (ref) vs. monthly vs. once vs. per visit vs. unspecified)

Freq_pervisit: Frequency of payment (dummy: annual (ref) vs. monthly vs. once vs. per visit vs. unspecified)

Freq_Unspec: Frequency of payment (dummy: annual (ref) vs. monthly vs. once vs. per visit vs. unspecified)

WTP: WTP results of the original study (corrected for inflation to the year 2017)

ln_WTP: Logarithm of the WTP results of the original study (corrected for inflation to the year 2017)

Units_mod: Unit of the willingness to pay ($ per person, household or per visit)

Units_perPerson: Unit of the willingness to pay (dummy: per household (ref) vs. per person vs. per visit)

Units_pervisit: Unit of the willingness to pay (dummy: per household (ref) vs. per person vs. per visit)

Animal_class: Animal class

Class_bird: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarinFish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_Freshwaterfish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_freshwaterMammal: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarineRiv_fish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarineReptile: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_TerrestrialMammal: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Mean_Lenght: Mean length (m)

ln_Mean_Lenght: Logarithm of the mean length

Mean_Weight: Mean weight (kg)

ln_Mean_Weight: Logarithm of the mean weight

 

 

1.2) 2017_WTP_MARINE_SPECIES_FRANCE

We extracted marine species form the IUCN database and only selected the ones belonging to the following group: Actinopterygii, Chondrichthyes, Mammalia, Reptilia. We extracted the average length and weight form the FishBase database (Actinopterygii, Chondrichthyes), Shirihai and Jarrett (2007; Mammalia) and Sea Turtle Conservancy database (Reptilia). We then applied the benefit transfer function (1) in order to calculate the WTP to conserve each species based on an annual tax payment per person in France. To be noted that the WTP for another country can be calculated by applying the relevant GDP-PPP to the benefit transfer function.

 

Field of the CSV file :

internalTaxonId: Identification from IUCN

kingdomName: Species kingdom

phylumName: Species phylum

orderName: Species order

className: Species class

familyName: Species family

genusName: Species genus

speciesName: Species

Genus_species: Genus species

redlistCategory_Local: Endangerment at the local scale

redlistCategory: Endangerment at the international scale

populationTrend: Global trend

Local_Stat_No(combined): Endangerment at the local  or international scale (if the local scale is not available) (dummy: endangered (ref) vs. not endangered)

Class_bird: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarinFish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_Freshwaterfish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_freshwaterMammal: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarineRiv_fish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarineReptile: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_TerrestrialMammal: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_Other: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

Class_MarinFish: Animal class (dummy: marine mammal (ref) vs. bird vs. marine fish vs. freshwater fish vs. freshwater mammal vs. diadromous fish vs. marine reptile vs. terrestrial mammal)

GDP_PPP_France: France GDP-PPP in 2017

Lmean: Mean length (m)

Wmean: Mean weigth (kg)

WTP_france_conser: WTP to conserve a population per year per person

 

2) LIMITATIONS AND WARNINGS

 

The values in the 2017_WTP_MARINE_SPECIES_FRANCE file can only be used separately in valuation processes, as these values are not additive (Beaumont, 2008). However, they can be used simultaneously as an indicator of people’s preferences for protecting a population in comparison to others (see figure provided).

To be noted that values for anguilliform fishes are to be taken with caution. As no species were comparable in terms of characteristics for building the benefit transfer function, the values for these species might be biased. The author might have eluded similar biases for other species. Dedicated studies to refine the results might be required for some species; this database only provides some basic values.