Reconceptualising the external validity of discrete choice experiments

Area of Science:

• Health Economics
• Decision Science
• Behavioral Economics

Background:

• External validity of Discrete Choice Experiments (DCEs) is critical for applying findings in clinical, commercial, and policy settings.
• Current research often focuses narrowly on comparing final outcomes, limiting the understanding of DCE generalizability.
• Existing empirical tests of external validity in health economics and other sectors are reviewed.

Purpose of the Study:

• To broaden the conceptualization of external validity beyond outcome comparison in DCEs.
• To introduce a new framework linking external validity to process validity and early DCE design.
• To suggest practical methods for exploring this comprehensive view of external validity.

Main Methods:

• Review of traditional theories and tests for external validity in DCEs.
• Analysis of empirical applications in health economics, transport, environment, and marketing.
• Development of a new conceptual model for external validity integrated with DCE process.

Main Results:

• Traditional external validity assessment in DCEs is often limited to predictive performance.
• A broader definition of external validity, encompassing process validity, is proposed.
• The study argues for pursuing external validity objectives from the initial conceptualization and design phase of DCEs.

Conclusions:

• External validity in DCEs requires a more holistic approach than solely comparing outcomes.
• Integrating process validity into DCE design enhances the pursuit of external validity.
• The proposed conceptualization offers innovative avenues for exploring and ensuring the external validity of DCE findings.