The purpose of the BUVD is to provide an educational and informational tool to the general public and interested specialists, documenting the economic values for beneficial uses of water identified by the California State Water Resources Control Board (SWRCB). It is envisioned that the BUVD be a companion to the Water Quality Standards Inventory Database (WQSID), which currently provides information to the public on water quality standards for, and beneficial uses of, water bodies throughout California, but no information on the value of those beneficial uses.
In preparing this alpha version of the database, the literature on economic values of water was consulted widely but not exhaustively, so in its current form the BUVD should be considered as:
- A representation of many, though not necessarily all, economic values for beneficial uses of water available in the current literature.
- A template which can be added to as more studies are identified as suitable for inclusion in the database over time.
The current version has a basic front-end search engine that simplifies use of the database for persons less familiar with Microsoft Access, relational databases, and query building. It is expected that the web-based version of the database to be implemented later will have a more powerful search engine that will allow users to do more complicated data searches.
A. Basic Structure and Contents
of the Beneficial Use Values Database
The beneficial use values database is a Microsoft Access relational database
with nine underlying tables. These tables contain the beneficial use values
that will appear in the web-based version and the documents in which they
were reported. The nine tables are linked. Currently, there are over 2000
values for a diverse set of amenities, including values for water for
recreation, habitat, municipal, and industrial uses.
The database design centers on the Documents table, which contains reference
information (pubyear, title, and refinfo), a field describing the type
of publication (pubtype), and general information specific to each document
(amenity, sitedesc, and comments). Documents were classified as one of
the following publication types:
- journal article,
- book/book chapter,
- report,
- unpublished/working paper, or
- other.
Of the 131 studies included
in the edited database, there were 8 books or book chapters, 101 journal
articles, 17 reports, and 5 working or unpublished papers. Because 6 of
the book chapters were separate chapters in 3 books, there are actually
128 distinctly different studies reported on in the database. The vast
majority of the studies were conducted in the last 25 years, which reflects
the relative paucity of studies valuing water and its uses in
the literature prior to the 1970s.
B. Valuation Methods Used
in Reported Studies
Market Valuation: When market data is available, market
price and quantity information can be used to estimate demand, supply,
or production relationships. These relationships provide a means for directly
measuring economic value.
Contingent Valuation Methods: Uses survey questions to obtain
direct estimates of WTP. This method is frequently used to value goods
for which there is little or no behavioral (market) data. It is also the
only method that can obtain estimates of nonuse values.
Conjoint Analysis: A survey-based approach in which people
are asked to rate or rank several different scenarios, each with different
levels of attributes taken from a common set. Statistical methods are
then used to estimate the WTP of individual attributes.
Damage Function Approach: These methods seek to determine
a "dose-response" relationship between an environmental quality
change and some physical effect, and then use market values for the estimated
marginal effect to determine a monetary value for the overall effect.
Hedonic Methods: Hedonic methods assume that the price of
a good is a function of its attributes. Thus, the price of a good is regressed
on its characteristics to find the marginal value of the characteristics.
Averting Behavior Approaches: Averting behavior approaches
infer the value people place on an amenity by what they spend to prevent
its removal or degradation.
Optimization Models: Optimization models are mathematical
representations of an economic problem and include mathematical programming,
calculus of variations, and optimal control models.
Opportunity Cost Method: This approach views the opportunity
cost associated with using an amenity for one use as the value of the
amenity used in its next best alternative use.
Simulation Models: Simulation models used in valuation of
beneficial uses are typically used to determine the biological or physical
response to economic stimuli.
Travel Cost Methods: Although there are many variants of
this approach, all TCM studies utilize expenditure and trip visitation
data for visitors to a natural resource to extrapolate the associated
value of a resource.
Replacement Cost Method: The replacement cost method uses
the monetary cost of replacing or restoring an amenity as a measure of
the value of the amenity.
Other Methods:
Valuation methods falling into this category represent a variety of approaches
to valuing beneficial uses that include three cost-based valuation techniques,
an energy analysis approach, and an agricultural yield comparison approach.
More information about the BUVD can be found in
Lew, Daniel K., Douglas M. Larson, Hiro Suenaga, and Rodrigo DeSousa. "
The Beneficial Use Values Database.
" Department of Agricultural and Resource Economics, April 2001.