Conservation Programs: Balancing Outcomes With a
Selection Index
Cynthia
Nickerson and Daniel
Hellerstein
Many of the Nation’s conservation
programs help to offset the negative effects of
agricultural production by enhancing water quality,
reducing soil erosion, and protecting wildlife habitats.
One tool many conservation program managers use
to balance multiple objectives is a “selection
index,” which allows them to rank and select
applicants based on how well the offered land provides
environmental improvements in a cost-effective manner.
In this index, different environmental and cost
objectives are weighted by program managers’
perceptions of their relative importance (see “Behind
the Data”). However, gauging which
environmental objectives should have the highest
priority in these programs is tricky because price
tags are generally not available to signal how much
people value improving wildlife nesting grounds,
for example, or making a stream clean enough for
swimming. If new information about environmental
preferences becomes available, program managers
can, in theory, adjust the weights to align future
program outcomes with the new preferences. In practice,
little is known about the actual effects of such
changes.
Using data from USDA’s Conservation
Reserve Program (CRP), the Nation’s largest
land retirement program, ERS researchers found that
small changes in index weights did not markedly
affect environmental outcomes at the national level.
But doubling the index weight on any one objective
(such as improving wildlife habitat) could result
in a 15-percent improvement in that outcome. These
findings suggest that if a conservation program
generates environmental improvements that approximately
match society’s preferences, little would
be gained by fine- tuning the index weights. But
if new information suggests that an alternative
mix of environmental improvements is preferred,
program outcomes can be affected by larger changes
in weights. Changes in weights may not induce proportional
changes in environmental improvements because some
factors, such as which land will be offered for
enrollment and which set of environmental problems
will be addressed in a voluntary program, cannot
be controlled.
Policymakers and program managers
may find that varying the index weights by region
or adjusting other program features, such as eligibility
criteria or the mix of allowable land management
practices, may also help bring about desired changes
in CRP
outcomes.
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