Rationalising the 'irrational': A think aloud study of discrete choice experiment responses

Mandy Ryan, Verity Watson, Vikki Entwistle

    Research output: Contribution to journalArticle

    106 Citations (Scopus)

    Abstract

    Stated preference methods assume respondents' preferences are consistent with utility theory, but many empirical Studies report evidence of preferences that violate utility theory. This evidence is often derived from quantitative tests that Occur naturally within, or are added to, stated preference tasks. In this study, we use qualitative methods to explore three axioms Of utility theory: completeness, monotonicity, and continuity. We take a novel approach, adopting a 'think aloud' technique to identify violations of the axioms Of utility theory and to consider how well the quantitative tests incorporated within a discrete choice experiment are able to detect these. Results indicate that quantitative tests classify respondents as being 'irrational' when qualitative statements would indicate they are rational'. In particular, 'non-nionotonic' responses can often be explained by respondents inferring additional information beyond what is presented in the task, and individuals who appear to adopt non-compensatory decision-making strategies do so because they rate particular attributes very highly (they are not attempting to simplify the task). The results also provide evidence of 'cost-based responses': respondents assumed tests with higher costs would be of higher quality. The value of including in-depth qualitative validation techniques in the development of stated preference tasks is shown. Copyright (C) 2008 John Wiley & Sons, Ltd.

    Original languageEnglish
    Pages (from-to)321-336
    Number of pages16
    JournalHealth Economics
    Volume18
    Issue number3
    DOIs
    Publication statusPublished - Mar 2009

    Keywords

    • stated preference
    • DCE
    • qualitative analysis
    • completeness
    • monotonicity
    • continuity
    • WILLINGNESS-TO-PAY
    • QUALITY-OF-LIFE
    • HEALTH-CARE
    • CONTINGENT VALUATION
    • ELECTIVE SURGERY
    • PREFERENCES
    • CONSISTENCY
    • PROVISION
    • ECONOMICS
    • PEOPLE

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