Geographical scoping and willingness-to-pay for nature protection

Figures & data

Figure 1. Example of a choice card.

Table 1. Coefficient estimates and marginal effects in brackets of the attribute only models (left) and full choice models (right) for versions CE1 and CE2.

	Attribute only models		Full models
	Model CE1	Model CE2	Model CE1	Model CE2
Nature in the own environment (u):
v unchanged	n.a.	−0.15 [n.s.]	n.a.	−0.26 [n.s.]
v small improvement	n.a.	0.62 [n.s.]	n.a.	0.43 [n.s.]
v large improvement	n.a.	1.37*** [0.04]	n.a.	1.17*** [0.04]
Nature in the Netherlands (x):
x unchanged	1.87*** [0.05]	0.45 [n.s.]	3.83*** [0.05]	0.39 [n.s.]
x unchanged × age^a	n.a.	n.a.	−0.04** [−0.01]	n.s.
x small improvement	2.49*** [0.06]	1.16*** [0.02]	5.52*** [0.07]	1.10*** [0.03]
x small improvement × age^a	n.a.	n.a.	−0.06** [−0.01]	n.s.
x small improvement × perceived importance nature^a	n.a.	n.a.	1.70***[0.21]	n.s.
x large improvement	2.74***[0.08]	1.07*** [0.04]	5.17*** [0.08]	0.98*** [0.04]
x large improvement × age^a	n.a.	n.a.	−0.05*** [−0.01]	n.s.
x large improvement × perceived importance nature^a	n.a.	n.a.	2.13***[0.21]	n.s.
Nature in the Caribbean Netherlands (y):
y unchanged	1.60*** [0.05]	0.19 [n.s.]	3.36*** [0.05]	0.18 [n.s.]
y unchanged × age^a	n.a.	n.a.	−0.04** [−0.01]	n.s.
y small improvement	1.72*** [0.04]	1.46*** [0.05]	4.98*** [0.05]	1.23*** [0.04]
y small improvement × age^a	n.a.	n.a.	−0.06*** [−0.01]	n.s.
y small improvement × perceived importance nature^a	n.a.	n.a.	1.26***[0.21]	n.s.
y large improvement	1.50*** [0.03]	1.00*** [0.03]	4.66*** [0.03]	1.08*** [0.03]
y large improvement × age^a	n.a.	n.a.	−0.05*** [−0.01]	n.s.
y large improvement × perceived importance nature^a	n.a.	n.a.	1.91*** [0.21]	0.71** [0.05]
y large improvement × female^a	n.a.	n.a.	−1.55***[−0.03]	n.s.
Nature rest of the world (v):
w unchanged	n.a.	0.32 [n.s.]	n.a.	0.33 [n.s.]
w small improvement	n.a.	0.81*** [0.03]	n.a.	0.77*** [0.03]
w large improvement	n.a.	1.17*** [0.03]	n.a.	1.16*** [0.03]
w large improvement × perceived importance nature^a	n.a.	n.a.	n.a.	1.07*** [0.05]
Tax	−0.08*** [−0.11]	−0.08*** [−0.13]	−0.11*** [−0.17]	−0.08*** [−0.15]
Tax × Income	n.a.	n.a.	0.01*** [0.05]	0.004** [0.02]
Constant of the no measures alternative	1.55***	−0.66 [n.s.]	0.40	−0.44
Standard deviations:
Error component	5.43***	5.90***	4.19***	5.31***
Parameter v unchanged	n.a.	1.72*	n.a.	1.79***
Parameter v small improvement	n.a.	1.13	n.a.	n.s.
Parameter v large improvement	n.a.	1.51**	n.a.	1.44***
Parameter x unchanged	2.51***	0.88	2.34***	n.s.
Parameter x small improvement	1.12*	1.39*	n.s.	n.s.
Parameter x large improvement	2.73***	2.33***	2.64***	1.89***
Parameter y unchanged	0.02	0.87	n.s.	n.s.
Parameter y small improvement	1.08	0.62	n.s.	n.s.
Parameter y large improvement	3.46***	1.47**	2.76***	n.s.
Parameter w unchanged	n.a.	0.77	n.a.	n.s.
Parameter w small improvement	n.a.	0.66	n.a.	n.s.
Parameter w large improvement	n.a.	3.66***	n.a.	3.19***
Log likelihood	−907	−1120	−778	−1054
AIC	1.30	1.39	1.28	1.38
Pseudo R^2	0.42	0.38	0.44	0.38
Number of observations	1416	1656	1254	1560

Notes: **, *** indicate, respectively, significance at the 5 and 1% level. n.s. stands for not significant and n.a. stands for not applicable. Estimations are performed with NLOGIT version 4 software.

^a The ME provided for interaction variables (x ₁ × x ₂) corresponds to the second variable (x ₂).

Table 2. Average WTP values (€ per month) for nature improvements according to the CE models.

	Nature Netherlands			Nature Caribbean Netherlands
	Unchanged	Small improvement	Large improvement	Unchanged	Small improvement	Large improvement
CE1	€22.39	€29.38	€29.22	€20.26	€20.85	€11.14
	(0.92)	(1.48)	(1.75)	(0.62)	(1.22)	(1.72)
CE2	n.s.	€16.24	€14.84	n.s.	€18.29	€13.80
		(0.08)	(0.48)		(0.09)	(0.50)
	Nature own environment			Nature rest of the world
	Unchanged	Small improvement	Large improvement	Unchanged	Small improvement	Large improvement
CE2	n.s.	n.s.	€17.47	n.s.	€11.47	€15.15
			(0.30)		(0.05)	(1.28)

Notes: Standard errors are shown between parentheses. n.s. stands for not significant.

Figure A1. Explanation of the attributes used in the choice experiment.

Figure A2. Levels of the nature attributes that were applied in the choice experiment.

Table

Nature in the own environment	Attribute CE coded as dummy variables of unchanged, small improvement and large improvement of nature in the respondent’s own environment
Nature in the Netherlands	Attribute CE coded as dummy variables of unchanged, small improvement and large improvement of nature in the Netherlands
Nature in the Caribbean Netherlands	Attribute CE coded as dummy variables of unchanged, small improvement and large improvement of nature in the Caribbean Netherlands
Nature rest of the world	Attribute CE coded as dummy variables of unchanged, small improvement and large improvement of nature in the rest of the world
Importance nature	Ordinal categorical variable, respondent’s perceived importance of nature
Tax	Attribute CE, continuous variable of the additional monthly tax to be paid for nature protection
Born in the Netherlands	Dummy variable of being born in the Netherlands
Female	Dummy variable of being female
Household size	Continuous variable of the number of household members
High education level	Dummy variable that the respondent has completed at least a Bachelor education
Age	Continuous variable of the age of the respondent
Income	Continuous variable of respondent’s monthly net household income (in thousand €)