A comparison of importance weights and willingness-to-pay measures derived from choice-based conjoint, constant sum scales and best-worst scaling

We review the measurement of product attribute importance, and find little consensus in definition or measurement methods. We compare four measurement methods: 1) two direct methods whereby respondents report the importance of attributes using best-worst scaling or constant sum scales, and 2) two indirect methods derived from discrete choice experiments. Our comparisons rely on previous findings that choice experiments are externally valid to use as the standard. We find high agreement within direct or indirect methods, but less agreement between direct and indirect methods. Our results also demonstrate that inferences derived from indirect measures appear to be susceptible to context effects related to the particular attributes a researcher chooses to investigate. We discuss implications for current and future research.