Communication à un séminaire :
(Queen’s University Belfast), « Response latency in stated choice experiments: Impact on preference, variance and processing heterogeneity »
, Environment Economics Seminar
, TSE, Toulouse, 7 mai 2012, 11:00-12:30, salle AMPHI S.
In this paper we utilise paradata relating to the response latency as a measure of the cognitive effort
invested by respondents in self-administered online stated preference surveys. While the effects of response
latency have been previously explored, this paper proposes a different approach. Specifically, we
attempt to disentangle preference, variance and processing heterogeneity and explore whether response
latency helps to explain these three types of heterogeneity. To test our methodology we use stated choice
data collected via an online survey to establish consumers’ preferences for various food attributes. Results
from our analysis reinforce that response latency has a bearing on the estimates of error variance
and the utility coefficients. Our findings raise concerns about the appropriateness of assuming deterministic
choice sets, and we also show a link between response latency and the consideration sets that
were actually used by respondents. We further observe that the manner in which response latency is
accommodated has implications for willingness to pay estimation. Importantly, results in this paper
draw attention for the need to better explain the variations that exist among respondents, in terms of
preferences, error variance and processing strategies, and that only focusing on one (or two) of these is
likely to lead to erroneous inferences.
Key words: choice experiments, willingness to pay, food choice, online surveys, paradata, response
latency, scale-adjusted latent class, independent availability logit.
Economie de l'environnement et ressources naturelles