In the past
few decades, the USEPA has widely recognized the importance of economic
analysis to the EPA mission. As a consequence, EPA has hired environmental economists
and supported research on benefits assessment. This has greatly enhanced EPA’s
knowledge base for decision support. EPA should now make a further significant
improvement to their decision support by establishing prescriptive decision
analysis as the best way to present uncertain scientific knowledge for informed
decision making.
Decision
analysis, based on the normative model of decision theory, is a
well-established discipline that is taught in many university public policy and
business programs. There are two fundamental elements in a decision analysis:
- A utility function that characterizes the values, or perhaps net benefits, associated with outcomes of interest that result from a management action,
- A probability model that quantifies the uncertainty in the outcomes of interest that result from a management action.
The economic analysis that is now embraced by EPA may be used
to provide the first element of the decision analysis quantifying value. An
uncertainty analysis can provide the second essential element.
Why has EPA recognized the importance of economic benefits
assessment to inform decision making, yet seems oblivious to the need to follow
the decision analysis model that is so well-established as an academic discipline?
I think that a major reason for this situation is that the environmental
engineering and ecology programs that have provided the academic training for
many scientists in EPA and in state environmental agencies do not include a
course in decision analysis, nor do they recommend a curriculum that includes
decision analysis taught in another academic department.
Perhaps to better appreciate the role of this
decision analytic framework, consider the following example from everyday life. All of us have made decisions on outdoor activities in consideration of the forecast
for rain. In deciding whether to hold or
postpone an outdoor activity, we typically seek (scientific) information on such
things as the probability
(reflecting uncertainty) of rain. Further,
it is not uncommon to hear the weather
forecast on the evening
news, but still defer a final
decision on the activity until an updated weather prediction in the morning (in other words,
get more sample information).
Beyond consideration of the scientific assessment in the weather forecast,
we also think about how important the activity is to us. Do we really want to
participate in the
activity, such that a little rain will not greatly reduce our enjoyment? Or, is the activity of only limited value, such that a small probability of rain may
be enough so that we choose not participate?
Every day, we make decisions based on an interplay, or mix, of uncertainty in an event (e.g., rain) and value (enjoyment) of an activity.
We are used to weighing these considerations in our minds and deciding. These same considerations--getting new information on the weather (which is analogous to supporting new scientific research, as in adaptive management), and deciding
how valuable the activity is to us (which is what we determine through cost/benefit analysis)--are key features of decision
analysis.
Public sector
decisions involving uncertain knowledge and uncertain forecasts should follow
this same decision analytic paradigm. Given the consequences of most public sector
decisions and the uncertainties in environmental modeling, it is essential that
this happen. Failure on the part of EPA to use decision analysis as their
prescriptive model for decision support means that many of EPA’s assessments
and models will continue to ignore uncertainty in model predictions, resulting
in many unexpected management outcomes because stakeholders are unaware of the
large uncertainties in predictions from the deterministic models that EPA
provides in its decision support. In my view, this situation is inexcusable.
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