The Impacts of Attribute Level Framing and Changing Cost Levels on Choice Experiments Value Estimates

Choice Experiments (CE) are increasingly used to estimate the values of environmental goods andservices. CE questionnaires represent the environmental good under valuation by varying levels ofnon-market attributes. Inclusion of a cost attribute enables the estimation of monetary values forchanges in the non-market attributes presented. The ways in which the levels of the attributes aredescribed in the survey - the ‘attribute frame’ - may affect respondents’ choices. Furthermore, varyinglevels of the cost attribute may impact CE value estimates. The challenge for CE practitioners is toidentify the ‘appropriate’ attribute frames and cost levels.In this paper, the impacts of changing cost levels and the impacts of describing non-market attributesas absolute levels or in relative terms are assessed. These tests were performed using data from a CEon catchment management in Tasmania, Australia. Contrary to a priori expectations, includingexplicit information cues about relative attribute levels in the choice sets is found not to affect statedpreferences. However, comparisons between different split samples provide evidence thatrespondents’ preferences are impacted by changing the range in cost attribute levels, with higherlevels leading to significantly higher estimates of WTP for one of the three environmental attributes.