question of embedding or sensitivity to scope, which is discussed in the Report of
the NOAA Panel on Contingent Valuation by Arrow et al. (1993) as well as in
other articles dealing with CVM (Carson 2000; Carson et al. 2000, 2003). The
concern is that the respondents are stating WTP without regard for the amount or
scope of the environmental good being offered. A larger mean difference was
found in the WTP of visitors to the nature reserve to eradicate the species compared with just containment. This gives some support to the idea that, among
visitors to the nature reserve at least, the difference between containment and
eradication was clear. The implication that they were willing to pay more for the
better environmental good is consistent with economic theory.
In addition to these two basic tests of conformity to economic theory, regression
analysis indicates two predictors of WTP, consistent with the results of previous
CVM studies: income level and membership in environmental organizations. The
regression analysis revealed that a higher level of income and membership in
environmental organizations correlated positively with a higher WTP (see
Sect. 14.4.4).
17.6.2 Use and Non-use Value
Contingent valuation is the only methodology that allows us to estimate non-use or
passive use value (sometimes referred to as existence value, first mentioned by
Krutilla 1967) (Carson 2000; Jakobsson and Dragun 2001; Carson et al. 2003). Our
study reveals that both for visitors to the Nizzanim LTER Coastal Sand Dune
Nature Reserve and the general population, the non-use or existence value of
containment or eradication of the invading species is greater than the use value.
This seems to indicate that the Israeli public, both visitors and non-visitors to the
nature reserve, recognize the value of conserving the nature reserve for its own
sake and not simply for its utility to human beings.
Fig. 17.1 Demand for invasive species control—demand curve for the environmental good. The
demand decreases as the price of the good increases for both questions
286
D. Lehrer et al.
the NOAA Panel on Contingent Valuation by Arrow et al. (1993) as well as in
other articles dealing with CVM (Carson 2000; Carson et al. 2000, 2003). The
concern is that the respondents are stating WTP without regard for the amount or
scope of the environmental good being offered. A larger mean difference was
found in the WTP of visitors to the nature reserve to eradicate the species compared with just containment. This gives some support to the idea that, among
visitors to the nature reserve at least, the difference between containment and
eradication was clear. The implication that they were willing to pay more for the
better environmental good is consistent with economic theory.
In addition to these two basic tests of conformity to economic theory, regression
analysis indicates two predictors of WTP, consistent with the results of previous
CVM studies: income level and membership in environmental organizations. The
regression analysis revealed that a higher level of income and membership in
environmental organizations correlated positively with a higher WTP (see
Sect. 14.4.4).
17.6.2 Use and Non-use Value
Contingent valuation is the only methodology that allows us to estimate non-use or
passive use value (sometimes referred to as existence value, first mentioned by
Krutilla 1967) (Carson 2000; Jakobsson and Dragun 2001; Carson et al. 2003). Our
study reveals that both for visitors to the Nizzanim LTER Coastal Sand Dune
Nature Reserve and the general population, the non-use or existence value of
containment or eradication of the invading species is greater than the use value.
This seems to indicate that the Israeli public, both visitors and non-visitors to the
nature reserve, recognize the value of conserving the nature reserve for its own
sake and not simply for its utility to human beings.
Fig. 17.1 Demand for invasive species control—demand curve for the environmental good. The
demand decreases as the price of the good increases for both questions
286
D. Lehrer et al.