ARE MORE PROFILES BETTER THAN LESS? SEARCHING FOR PARSIMONY AND RELEVANCE IN STATED CHOICE EXPERIMENTS

Transportation planners increasingly include a stated choice (SC) experiment as part of the armory of empirical sources of information on how individuals respond to current and potential travel contexts. The accumulated experience with SC data has been heavily conditioned on analyst prejudices about the acceptable complexity of the data collection instrument, especially the number of profiles (or treatments) given to each sampled individual (and the number of attributes and alternatives to be processed). A review of the literature suggests that very little is really known about the basis for rejecting complex designs or accepting simple designs. Although it is appreciated that more complex designs provide the analyst with increasing degrees of freedom in the estimation of models, facilitating non-linearity in main effects and independent two-way interactions, it is by no means clear what the overall behavioral gains are to increasing the number of treatments. In this paper, we develop a complex design as the basis for a stated choice study, producing a fractional factorial of 32 rows. However we then truncate the fraction by administering 4, 8, 16, 24 and 32 profiles to a sample of individuals in Australia and New Zealand faced with the decision to fly (or not to fly) between Australia and New Zealand by either Qantas or Ansett under alternative fare regimes. Statistical comparisons of elasticities (an appropriate behavioral basis for comparisons) suggest that the empirical gains within the context of a linear specification of the utility expression associated with each alternative in a discrete choice model may be quite marginal. (a)

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  • Corporate Authors:

    RAILTRACK PLC

    RAILTRACK HOUSE, EUSTON SQUARE
    LONDON,   United Kingdom  NW1 2EE
  • Authors:
    • Stopher, P
    • Hensher, D A
  • Publication Date: 1999-6

Language

  • English

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Filing Info

  • Accession Number: 00793576
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Jun 15 2000 12:00AM