Economic Measures of Soil Conservation Benefits: Regional Values for Policy Assessment
by
LeRoy Hansen and
Marc RibaudoTechnical Bulletin No. (TB-1922) 31 pp, September 2008
Annual conservation program expenditures have doubled to more
than $5 billion per year over the last decade. A major focus of
these programs is on reducing soil erosion. This report describes
the per-ton values of 14 types of soil conservation benefits. The
values are derived from models that capture the cause-and-effect
relationships between agricultural erosion and environmental
benefits. Values and methodology are described so that analysts can
apply the data to calculate regional and national benefits of
specific soil conservation projects. Analysts can also use the
per-ton benefit estimates to determine where a 1-ton reduction in
soil erosion might be most beneficial.
What Is the Issue?
Conservation programs best serve the public when their funding,
design, and implementation maximize benefits relative to costs.
Unlike the cost of soil conservation efforts, environmental
benefits of decreasing soil erosion are not easy to measure.
Information on the values of soil conservation benefits can aid in
designing more cost-effective programs and evaluating
accomplishments of programs, policies, and practices.
What Does the Report Do?
Past research has generated per-ton soil conservation benefit
estimates for 14 types of environmental benefits that are suitable
for use in national analyses. The benefit types can be placed in
three general categories:
Twelve benefit types reflect soil conservation impacts on water
quality and the subsequent impacts on industries, municipalities,
and households.
- One benefit type captures the effect of wind erosion reductions
on household cleaning costs.
- One benefit type has values of soil productivity preserved
through reductions in wind and water erosion.
The report describes the development of each estimate, and
provides some insight into regional variations in soil conservation
benefits. The values can be viewed as prices that people,
businesses, and government agencies would be willing to pay for a
1-ton reduction in soil erosion. For example, the reduction in
municipal water-treatment costs due to a 1-ton reduction in erosion
represents municipalities' willingness to pay for that much reduced
erosion.
The per-ton benefit values are available on the ERS web site in
two databases. One provides per-ton benefits of soil erosion
reduction for the 3,074 counties within the 48 contiguous States.
The other provides per-ton benefits for the 2,111 8-digit
Hydrologic Unit Code (HUC) watersheds within the contiguous States.
While the benefit categories in these data encompass many of the
benefits of soil conservation, the categories do not measure every
benefit. For example, some people may value knowing that water
quality is improved-even though they do not use the water-or that
endangered species have an improved habitat, but estimates of these
benefits are not available. As a result, applications of the
available data will provide lower-bound estimates of total soil
conservation benefits.
How Was the Study Conducted?
The per-ton benefit estimates are derived from models developed
since the 1980s by ERS. The estimates are believed to be the best
available for national analyses of soil conservation benefits, and
the ERS data are updated as improved models become available. Four
of the models generate marginal dollar-per-ton benefit estimates;
the others generate average per-ton estimates. Descriptions of the
economic frameworks, data sources, and models supporting estimates
within each of the 14 benefit categories were synthesized from USDA
published reports and peer-reviewed journal articles. All of the
reported values were adjusted for inflation by the Consumer Price
Index, so that all values are in year 2000 dollars. The values can
be directly applied to observed and potential changes in soil
erosion. They can also be applied to nonagricultural changes in
soil erosion, as long as the changes are appropriately calibrated.
Although the data have county- and HUC-level values, the benefit
values are credible only when reported at national and multi-State
levels. The model descriptions provide insights on how the benefit
values can best be applied and results interpreted. Values are
reported by category, so users can choose those they feel are
appropriate to their own applications.