Image management and self deception response biases in stated preference studies: A contingent and inferred valuation study for the preservation of a wetland in South Australia

Stated preference studies have come under considerable scrutiny due to their lack of clear incentive compatibility, and the evidence for response biases leading to inflated estimates of Willingness To Pay (WTP). A Contingent Valuation (CV), augmented with the Inferred Valuation (IV) method of Lusk and Norwood (J. Env. Econ. Mgmt. 2009) study was undertaken using an internet panel of 1000 respondents considering the WTP to preserve an at-risk wetland in the Upper South East region of South Australia – a region in which few pristine wetlands remain after substantial pastoral and farming development in the last 50 years. The IV approach has been shown to generate substantially lower WTP than the CV approach, but the source of these deviations has not been formally considered. This paper presents an outline of how ‘Image Management’ and ‘Self-Deception’ may generate CV-IV deviations and presents a formal test of their contribution to these.