The economics of climate change impacts à la Stern: Novel and nuanced or rhetorically restricted?

The contingent valuation method has become an established and major part of the toolbox
used to produce monetary values for evaluating environmental changes. It has been used to inform
everything from the value of ecosystem services to cultural heritage to loss of life. The method has
been highly controversial at various stages but despite this, or perhaps due to the publicity, it has
grown in scope and scale. Numerous occurrences of `bias' and `anomalies' in results have been
addressed by improved design, so providing guidance on perfected approaches to making sure
respondents reveal preferences in accord with theoretical expectations. That respondents may not
wish to and often fail to conform is seen as a challenge for the design team to be more ingenious with
their incentive mechanisms which get respondents to act `rationally'. Failing this, data can be
classified and treated to derive `conservative' results. I document in this paper how whole areas of
evidence from contingent valuation have been removed from consideration by design, with respond-
ents expected to conform to an idealised rational agent model or to suffer branding and exclusion as
having the `wrong motives'. While the method is then susceptible to manipulation (eg to meet
sponsors' requirements), if used more scientifically it also holds the potential to reveal fundamental
flaws in economic theory and ways to advance that same theory.