For better or worse? Investigating the validity of best-worst scaling experiments in health
Choice experiments are frequently used in health economics to measure preferences for non-market goods. Best worst discrete choice experiment (BWDCE) has been proposed as a variant of the traditional “pick the best” approach. BWDCE, where participants choose the best and worst options, is argued to generate more precise preference estimates because of the additional information collected. However, for this to be the case two conditions must hold: (i) best and worst decisions provide similar information about preferences, and (ii) asking individuals to answer more than one choice question per task does not reduce data quality. Whether these conditions hold remains under researched. This is the first study to compare participants’ choices across three experimental conditions: (i) BEST choices only, (ii) WORST choices only, and (iii) BEST & WORST choices (BWDCE). We find responses to worst choices are noisier. Implied preferences from the best only and worst only choices are qualitatively different, leading to different WTP values. Respondents to BWDCE tasks are of lower quality and respondents are more likely to use simplifying decision heuristics.
Outcome and Translation
As BWDCE is being increasingly used in health economics we encourage further investigation of the method and identify important area for future research.
HERU researchers involved in this research project: Nicolas Krucien and Mandy Ryan
External collaborator: J. Sicsic (INSERM)
Krucien, N., Sicsic, J. and Ryan, M. (2019) 'For better or worse? Investigating the validity of best–worst discrete choice experiments in health', Health Economics, 28(4), 572-586.