with a basic level of an environmental good. He is next presented with an alternative
option where the environmental good has been improved or increased, but at a price.
The respondent is requested to choose between the two. The amount of the increase
is then changed until the respondent perceives no relative advantage of one alternative over the other.
The result may be perceived as the marginal compensated cost for the environmental feature, service or good.
8.8.5 Costless Choice
In this method, participants are presented with several alternatives, each costing
nothing, but nevertheless desirable ones. This is then followed by questions to the
participants to elicit their preference.
For example, imagine being given a choice among:
1. a given sum of money
2. an unpriced environmental good such as
(a) decreased air pollution
(b) reduced noise levels
(c) increased accessibility to public recreation facilities.
If the environmental good is selected instead of the money, this indicates
the minimum (lower limit) value of the environmental good to that individual. If
the individual selects the money instead, the inference is that the individual perceives
the environmental good to have a lower value than the sum of money.
Variations of this method include the choice of the unpriced environmental good
(e.g spending a day in a park, or by a lake) against several goods (soft drink, meal,
movie ticket, etc.) of differing values. Such an approach might, in some countries, be
more applicable than the bidding game method, which some people might perceive
as being abstract.
8.8.6 Delphi Technique
This method requires the compilation of a list of experts to participate in the process.
Each of these experts will then be requested to set a value or price on a specific
environmental good.
The values or prices obtained are then disseminated with each expert’s justification for his choice. After looking at these justifications, the experts are requested to
review their estimates and to reach a new decision. It is expected that after successive
rounds, the values come closer to each other until finally, they form a tight cluster
around an average value.
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8 Analysis of Environmental Impacts of Infrastructure
option where the environmental good has been improved or increased, but at a price.
The respondent is requested to choose between the two. The amount of the increase
is then changed until the respondent perceives no relative advantage of one alternative over the other.
The result may be perceived as the marginal compensated cost for the environmental feature, service or good.
8.8.5 Costless Choice
In this method, participants are presented with several alternatives, each costing
nothing, but nevertheless desirable ones. This is then followed by questions to the
participants to elicit their preference.
For example, imagine being given a choice among:
1. a given sum of money
2. an unpriced environmental good such as
(a) decreased air pollution
(b) reduced noise levels
(c) increased accessibility to public recreation facilities.
If the environmental good is selected instead of the money, this indicates
the minimum (lower limit) value of the environmental good to that individual. If
the individual selects the money instead, the inference is that the individual perceives
the environmental good to have a lower value than the sum of money.
Variations of this method include the choice of the unpriced environmental good
(e.g spending a day in a park, or by a lake) against several goods (soft drink, meal,
movie ticket, etc.) of differing values. Such an approach might, in some countries, be
more applicable than the bidding game method, which some people might perceive
as being abstract.
8.8.6 Delphi Technique
This method requires the compilation of a list of experts to participate in the process.
Each of these experts will then be requested to set a value or price on a specific
environmental good.
The values or prices obtained are then disseminated with each expert’s justification for his choice. After looking at these justifications, the experts are requested to
review their estimates and to reach a new decision. It is expected that after successive
rounds, the values come closer to each other until finally, they form a tight cluster
around an average value.
236
8 Analysis of Environmental Impacts of Infrastructure