39
and Tour Time is positive, on the other hand, the coefficients of Tour Time
2
, Tour Fee
are negative. While standard deviation of Tour Time coefficient is not significant, the
other variables’ standard deviation of coefficients is also significant: there is preference heterogeneity.
Table 3.2 also shows the effect of ecological information provision, and they are
not significant except for Carp Removal option. The coefficient of the effect of ecological information on Carp Removal option is significantly positive
(Coefficient = 0.403; SE = 0.176), namely, information provision dramatically
increased the probability of choosing canoe tours including carp removal (Fig. 3.3).
The coefficient of Carp Removal option for respondents who were provided with
information could be calculated through addition of the coefficient of Carp Removal
option and the effect of ecological information on Carp Removal option, which had
a positive result (Coefficient = 0.0368). Therefore, the utility of respondents had
ecological information became positive if the option for carp removal was added to
canoe tours, and the mean WTP for Carp Removal option by respondents who had
ecological information was estimated at 99.3 JPY.
Table 3.2 Estimation results using the random parameter logit model
Variable
Random parameter model
Mean of coefficient
(S.E)
Standard deviation of
coefficient (S.E)
Random and nonrandom parameters in utility function
Carp removal option
−0.366 (0.131)
∗∗∗
1.01 (0.112)
∗∗∗
Tour time ∗10
−1
0.395 (0.136)
∗∗∗
0.00112 (0.0374)
Tour time
2
∗10
−4
−1.52 (0.586)
∗∗∗
0.986 (0.117)
∗∗∗
Pick-up option
0.405 (0.110)
∗∗∗
0.719 (0.107)
∗∗∗
Tour fee ∗10
−3
−0.741 (0.0514)
∗∗∗
–
Non-attendance
(alternative-specific constant)
−1.25 (0.818)
2.52 (0.329)
∗∗∗
The effect of ecological information on each random parameter variable
Carp removal option
0.403 (0.176)
∗∗
Tour time ∗10
−1
−0.0283 (0.177)
Tour time
2
∗10
−4
−0.324 (0.768)
Pick-up option
0.0138 (0.146)
Non-attendance
(alternative-specific constant)
0.0273 (1.08)
Number of observations
1608
Log likelihood
−1243.10
Simulated maximum likelihood was conducted using Halton draws with 1000 replications
Please, see Train 2003 for details on Halton draws
Carp Removal option: availability of options for carp capture; Pick-up option: collection and transport to the recreational site by guides; Tour Time: duration of tour (h); Tour Time
2
: Tour Time
squared; Tour Fee (JPY). Carp Removal option and Pick-up option were applied effect coding;
Tour Fee, Tour Time, and Tour Time
2 were normalized
∗∗∗p < 0.001, ∗∗p < 0.01, ∗p < 0.05
3 How to Engage Tourists in Invasive Carp Removal: Application of a Discrete Choice…
and Tour Time is positive, on the other hand, the coefficients of Tour Time
2
, Tour Fee
are negative. While standard deviation of Tour Time coefficient is not significant, the
other variables’ standard deviation of coefficients is also significant: there is preference heterogeneity.
Table 3.2 also shows the effect of ecological information provision, and they are
not significant except for Carp Removal option. The coefficient of the effect of ecological information on Carp Removal option is significantly positive
(Coefficient = 0.403; SE = 0.176), namely, information provision dramatically
increased the probability of choosing canoe tours including carp removal (Fig. 3.3).
The coefficient of Carp Removal option for respondents who were provided with
information could be calculated through addition of the coefficient of Carp Removal
option and the effect of ecological information on Carp Removal option, which had
a positive result (Coefficient = 0.0368). Therefore, the utility of respondents had
ecological information became positive if the option for carp removal was added to
canoe tours, and the mean WTP for Carp Removal option by respondents who had
ecological information was estimated at 99.3 JPY.
Table 3.2 Estimation results using the random parameter logit model
Variable
Random parameter model
Mean of coefficient
(S.E)
Standard deviation of
coefficient (S.E)
Random and nonrandom parameters in utility function
Carp removal option
−0.366 (0.131)
∗∗∗
1.01 (0.112)
∗∗∗
Tour time ∗10
−1
0.395 (0.136)
∗∗∗
0.00112 (0.0374)
Tour time
2
∗10
−4
−1.52 (0.586)
∗∗∗
0.986 (0.117)
∗∗∗
Pick-up option
0.405 (0.110)
∗∗∗
0.719 (0.107)
∗∗∗
Tour fee ∗10
−3
−0.741 (0.0514)
∗∗∗
–
Non-attendance
(alternative-specific constant)
−1.25 (0.818)
2.52 (0.329)
∗∗∗
The effect of ecological information on each random parameter variable
Carp removal option
0.403 (0.176)
∗∗
Tour time ∗10
−1
−0.0283 (0.177)
Tour time
2
∗10
−4
−0.324 (0.768)
Pick-up option
0.0138 (0.146)
Non-attendance
(alternative-specific constant)
0.0273 (1.08)
Number of observations
1608
Log likelihood
−1243.10
Simulated maximum likelihood was conducted using Halton draws with 1000 replications
Please, see Train 2003 for details on Halton draws
Carp Removal option: availability of options for carp capture; Pick-up option: collection and transport to the recreational site by guides; Tour Time: duration of tour (h); Tour Time
2
: Tour Time
squared; Tour Fee (JPY). Carp Removal option and Pick-up option were applied effect coding;
Tour Fee, Tour Time, and Tour Time
2 were normalized
∗∗∗p < 0.001, ∗∗p < 0.01, ∗p < 0.05
3 How to Engage Tourists in Invasive Carp Removal: Application of a Discrete Choice…