Strategic behaviour in choice experiments.

Practitioners of environmental economics sometimes use repeated trinary choice experiment surveys to estimate the value of environmental policies and programs for use in policy evaluation. These surveys have several advantages over simpler forms of non-market valuation: (1) researchers can estimate the marginal value of attributes of the good or service in question, making the results useful for benefits transfer; and (2) because respondents make several choices and choose from choice sets containing three options, efficiency of the willingness to pay estimate is improved over one-shot, binary choice formats. Despite these benefits, such surveys may have incentive properties which cause the resulting value estimates to be biased. This paper presents a theoretical demonstration that subjects often have an incentive to choose the second-best option in a repeated trinary choice survey. The model shows that due to the nature of factorial choice set design, the second-best option in the choice set will often be the status quo option. The paper reports a set of experiments designed to test these theoretical predictions in an induced-value setting. The experimental results are consistent with the theoretical predictions, demonstrating that repeated trinary choice experiment surveys can generate biased value estimates under a wide range of conditions.

Content Validity in Landscape Valuation: A transdisciplinary approach to valuing the landscape of the peninsula of Sorrento, Italy.

This paper addresses the representation of landscape complexity in stated preferences research. It integrates landscape ecology and landscape economics and conducts the landscape analysis in a three-dimensional space to provide ecologically meaningful quantitative landscape indicators that are used as variables for the monetary valuation of landscape in a stated preferences study. Expected heterogeneity in taste intensity across respondents is addressed with a mixed logit model in Willingness to Pay space. The results suggest that the integration of landscape ecology metrics in a stated preferences model provides useful insights for valuing landscape and landscape changes