Abstract:
Stated choice (SC) experiments are increasingly adopted as the empirical source 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). It is not uncommon for analysts to impose very
stringent limitations on the complexity of an SC experiment. A review of the literature suggests that very little is known about the
basis for rejecting complex designs or accepting simple designs. In this paper, we develop a complex design as the basis for an SC
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 alternative airlines and fare regimes. Statistical comparisons of elasticities (an appropriate behavioural 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.
