Are Best and Worst Choices Inconsistent? An Evaluation of the Evidence, and a Proposal for Maximising the Value of Best-Worst Scaling Data
Best-worst scaling (BWS) is an increasingly popular method to assess preferences in environmental management. BWS provides more information per choice task, because respondents provide information about their best and worst choices. An important assumption is that their utility function is the same when they are making both choices. However, empirical evidence shows that this does not always hold. A systematic review of the relevant agricultural and environmental economics literature (n = 119) reveals that most studies (114) do not test whether best and worst choices are consistent, but assumed they were. Among the papers that do test, there is no consistent procedure to assess consistency between best and worst choices, or guidance on how to proceed if inconsistency is found. In this research, we demonstrate how inconsistency between best and worst choices can be distinguished from heterogeneity in preferences, and how to identify the segment(s) of the sample that genuinely have inconsistencies between best and worst choices. We illustrate our approach with a case study, whose results show that inconsistent best and worst choices may only be a problem for a subset of respondents. Using our method, the full benefits of BWS can be achieved