Abstract:
The management options chosen by decision makers in
managing wildlife and fisheries have different effects for
diverse user groups. As a result, natural resource management
agencies often seek information to evaluate the effects of
alternative policies on the benefits provided to different
constituencies. Over the past decade, economists have
developed techniques to measure the benefits provided by such
nonmarket goods.
The random utility model (RUM), a variant of the travel
cost model (TCM), is one of the techniques developed by
economists to measure benefits associated with changes in the
quantity or quality of nonmarket goods. The advantages of
using RUN over other techniques are that the substitution
effects among different sites providing similar recreational
activities or services can be incorporated into the model to
avoid overestimating the benefits provided by a certain site.
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RUM is used in this thesis to measure the welfare changes
caused by a reduction in fishing quality or closure of one of
the sites in a recreational fishing area. The focus of this
study is the spring chinook recreational fishery in the lower
Willamette River. The 1988 Willamette Run Spring Chinook
Survey and the 1988 Willamette River Spring Chinook Salmon Run
Report, published by the Oregon Department of Fish and
Wildlife, provide the data set to do this research. Three
definitions of travel costs, TC1, TC2, and TC3 are derived
from the data set and used alternatively in the RUM framework.
Specific objectives of this thesis include: (1) estimate
how the attributes of a site (travel cost, congestion level
and fishing quality of the site) will affect the individual's
site choice; and (2) estimate the welfare changes arising from
the two hypothetical policies which change the quality of
fishing experience and which restrict the access of anglers to
a certain fishing site.
The results indicate that fishing sites on the Willamette
River are more attractive to anglers if the fishing quality is
increased, if more people visit, and if the site is relatively
inexpensive to reach. The results of the elasticities of
probabilities show that the travel cost has the largest effect
on individual site choice decision.
For different definitions of travel costs, the estimated
welfare losses caused by the first hypothetical policy (of a
reduction in fishing. success) for a representative angler in
the sample are $ 0.37, $ 0.91, and $ 0.47 respectively, per
trip. For different definitions of travel costs, the aggregate
welfare losses associated with this hypothetical policy are $
82,309, $ 202,436, and $ 104,555.
For different definitions of travel costs, the estimated
welfare losses caused by the second hypothetical policy (a
closure of one site) for a representative angler in the sample
are $ 3.82, $ 54.91, and $ 4.83 per trip respectively. The
aggregate welfare losses associated with this hypothetical
policy are $ 849,786, $ 12,215,114, and $ 1,074,467
respectively for TC1, TC2, and TC3.
Assuming that these two policies achieved the same
objectives, the policy implication of these results is that
the first policy is preferred because the welfare loss is much
smaller than the second one.
There is a methodological implication suggested by one of
the findings. A few of the individual results obtained from
the model with TC2 travel cost violate the assumption of
utility maximization. This implies that TC2 may over-value the
opportunity cost of time in the travel cost variable, and
points out the uncertain of the definition of travel cost used
in RUM analyses.
