Article Figures & Data
Figures
- Figure 1
Choice Card Example for the Two Single-Site Discrete Choice Experiments (above) and the Multiple-Site Discrete Choice Experiment (below)
Tables
Attribute Attribute Levels Length of the river section that would be restored 0 km,a 0.5 km, 1 km, 2 km Walking along the river Yes, Noa Swimming in the river Yes, Noa Barbecuing on the river bank Yes, Noa Biodiversity Low (60% of potential plant and animal species present)a Medium (75% of potential plant and animal species present) High (100% of potential plant and animal species present) Price (increase in canton taxes per person per year) 0 CHF,a 25 CHF, 50 CHF, 100 CHF, 150 CHF, 250 CHF, 500 CHF ↵a Attribute level in the status quo alternative. The status quo levels for the length and price attributes could not appear in the hypothetical choice alternatives. CHF, Swiss francs.
Variable Description Coding and Units Length of the river section that would be restored Choice attribute; indicates the length of the river restoration project Continuous variable; in kilometers Walking along the river Choice attribute; indicates whether river restoration would provide an option to walk along the river Dummy variable, 1 = Walking along the river is possible Swimming in the river Choice attribute; indicates whether river restoration would provide an option to swim in the river Dummy variable, 1 = Swimming in the river is possible Barbecuing on the river bank Choice attribute; indicates whether river restoration would provide an option to barbecue on the river bank Dummy variable, 1 = Barbecuing on the river bank is possible High biodiversity Choice attribute; indicates whether river restoration would increase biodiversity to a high level Dummy variable, 1 = High biodiversity level is achieved (100% of potential plant and animal species are present) Medium biodiversity Choice attribute; indicates whether river restoration would increase biodiversity to a medium level Dummy variable, 1 = Medium biodiversity level is achieved (75% of potential plant and animal species are present) Price Choice attribute; indicates an increase in annual canton taxes per person for the purpose of river restoration Continuous variable; in Swiss francs Walking attribute × Respondents who walk when visiting the rivers Interaction term between the choice attribute for walking and a dummy variable indicating whether the respondent usually walks when visiting the rivers Dummy variable, 1 = Walking along the river is possible and respondent usually walks when visiting the rivers Swimming attribute × Respondents who swim when visiting the rivers Interaction term between the choice attribute for swimming and a dummy variable indicating whether the respondent usually swims when visiting the rivers Dummy variable, 1 = Swimming in the river is possible and respondent usually swims when visiting the rivers Barbecuing attribute × Respondents who barbecue when visiting the rivers Interaction term between the choice attribute for barbecuing and a dummy variable indicating whether the respondent usually barbecues when visiting the rivers Dummy variable, 1 = Barbecuing on the river bank is possible and respondent usually barbecues when visiting the rivers ln(Road distance to the Thur + 1) Natural logarithm of road distance between respondent’s home and the river Thur Continuous variable; road distance in kilometers Road distance to the Töss Road distance between respondent’s home and the river Töss Continuous variable; in kilometers Road distance to the valued river × Respondents living in urban areas Interaction term between the linear road distance to the valued river and a dummy variable indicating whether the respondent lives in an urban area (towns with >20,000 inhabitants) Continuous variable; in kilometers Longitudinal distance to the valued river Euclidean (air) distance between respondent’s home and the valued river site in the East-West direction Continuous variable; in kilometers; positive (negative) values indicate East (West) Latitudinal distance to the valued river Euclidean (air) distance between respondent’s home and the valued river site in the North-South direction Continuous variable; in kilometers; positive (negative) values indicate North (South) cosθ Cosine of the angle between respondent’s home and the valued river site Continuous variable; range: –1 to 1; positive (negative) values indicate East (West) sinθ Sine of the angle between respondent’s home and the valued river site Continuous variable; range: –1 to 1; positive (negative) values indicate North (South) SDCE (1) Thur SDCE (2) Töss MDCE Variable (3) Thur (4) Töss Mean Estimates of Random Parameters Constant –1.690
(6.010)–27.741***
(10.103)–41.346**
(16.331)5.140
(12.584)Length of the river section that would be restored 1.161**
(0.455)0.617**
(0.255)7.828***
(2.142)6.905***
(2.114)Walking along the river 3.471***
(1.110)2.042***
(0.532)26.927***
(6.846)2.411
(1.991)Swimming in the river 1.112*
(0.609)0.923**
(0.387)9.716***
(2.605)4.680**
(2.100)Barbecuing on the river bank 1.917***
(0.717)–0.048
(0.411)2.520
(1.701)1.280
(1.365)High biodiversity 1.936**
(0.838)0.752
(0.493)15.703***
(4.312)11.947***
(3.894)Medium biodiversity 0.979
(0.786)0.454
(0.508)13.282***
(3.554)12.814***
(4.185)Price –0.062***
(0.017)–0.024***
(0.004)–0.081***
(0.020)–0.081***
(0.021)Nonrandom Parameters Walking attribute × Respondents who walk when visiting the rivers 3.400***
(1.303)2.005***
(0.573)2.078
(2.165)16.740***
(4.576)Swimming attribute × Respondents who swim when visiting the rivers 2.923***
(0.880)1.791***
(0.528)7.780***
(2.558)6.396**
(2.602)Barbecuing attribute × Respondents who barbecue when visiting the rivers 3.985***
(1.046)2.101***
(0.617)18.774***
(4.835)7.586**
(3.200)ln(Road distance to the Thur + 1) –7.572**
(3.766)10.393***
(3.468)4.404
(6.091)–3.248
(4.578)Road distance to the Töss 0.887***
(0.276)–0.465***
(0.101)–0.865***
(0.289)–1.033***
(0.282)Road distance to the valued river × Respondents living in urban areas 0.871***
(0.240)0.173***
(0.058)5.511***
(1.595)0.588***
(0.198)Longitudinal distance to the valued river –0.101
(0.070)–0.109
(0.077)–0.805***
(0.222)–1.053***
(0.295)Latitudinal distance to the valued river –0.829***
(0.270)0.106
(0.116)0.208
(0.251)–0.871***
(0.289)cosθ 0.571
(0.714)–0.792
(0.652)–7.696***
(2.180)0.315
(0.885)sinθ 1.346
(0.845)0.562
(0.486)2.916***
(1.203)3.077***
(1.118)Standard Deviations of Random Parameters Constant 7.090***
(1.727)4.226***
(0.736)6.601***
(1.850)7.266***
(1.844)Length of the river section that would be restored 2.340***
(0.580)1.389***
(0.310)10.456***
(2.663)10.684***
(2.571)Walking along the river 8.199***
(2.039)4.719***
(0.804)39.451***
(9.658)27.737***
(7.135)Swimming in the river 4.049***
(1.064)3.694***
(0.713)31.070***
(7.867)9.686***
(2.441)Barbecuing on the river bank 4.973***
(1.448)4.863***
(0.774)34.740***
(8.600)28.724***
(7.532)High biodiversity 6.163***
(1.617)2.261***
(0.751)22.656***
(5.363)3.357**
(1.641)Medium biodiversity 2.992**
(1.456)0.726
(0.676)18.480***
(4.695)0.091
(2.206)Price 0.055***
(0.016)0.026***
(0.004)0.076***
(0.019)0.102***
(0.026)Log-likelihood –781.67 –893.08 –1,004.53 Likelihood ratio test (χ2) 1,508.37*** 1,311.94*** 1,154.94*** Pseudo R2 0.491 0.423 0.365 AIC/Na 1.155 1.304 1.467 Number of observations 1,398 1,410 1,440 - Table 4
Extended Models: Marginal Willingness-to-Pay Estimates per Person per Year, in Swiss Francs
Choice Attribute SDCE Thur SDCE Töss MDCE Between SDCE and MDCE Thur Between SDCE and MDCE Töss Thur Töss Length of the river section that would be restored (in kilometers) 18.74
(7.37)26.19
(12.42)96.09
(21.03)85.74
(19.21)p < 0.01 p < 0.01 Walking along the river 56.05
(18.52)86.62
(24.89)330.54
(44.44)29.94
(25.54)p < 0.01 p < 0.05 Swimming in the river 17.96
(9.79)39.17
(18.04)119.27
(28.11)58.12
(24.29)p < 0.01 p = 0.26 Barbecuing on the river bank 30.96
(11.50)–2.05
(17.33)30.93
(22.32)15.90
(17.35)p = 0.48 p = 0.23 High biodiversity 31.27
(12.59)31.91
(23.43)192.76
(36.70)148.35
(38.53)p < 0.01 p < 0.01 Medium biodiversity 15.81
(12.63)19.25
(22.91)163.05
(29.88)159.12
(41.82)p < 0.01 p < 0.01 Note: Standard errors are reported in parentheses. MDCE, multiple-site discrete choice experiment; SDCE, single-site discrete choice experiment.
Hypothesis Outcome 
Rejected for 4 out of 5 nonmonetary choice attributes Rejected for 3 out of 5 nonmonetary choice attributes Thur SDCE Toss SDCE Thur MDCE Toss MDCE Cannot be rejected Cannot be rejected Rejected Cannot be rejected Rejected Rejected Cannot be rejected Cannot be rejected Cannot be rejected Rejected Rejected Cannot be rejected Rejected in favor of (substitution)Rejected in favor of (substitution)Rejected in favor of (compl ementarity)Cannot be rejected Cannot be rejected for SDCEs; cannot be rejected for MDCE Note: MDCE, multiple-site discrete choice experiment; SDCE, single-site discrete choice experiment.
