01371614

Component

Choice modelling surveys routinely include questions about perceptions and attitudes. While researchers have occasionally included responses to such questions in their models in a deterministic fashion, it is well known that this can lead to endogeneity bias. This has led to a growing popularity for latent variable approaches that jointly model the response to stated choice tasks and attitudinal questions. Such hybrid frameworks have proved fruitful in explaining differences in sensitivities across respondents. At the same time, a separate stream of research has started to openly question the nature of the taste heterogeneity retrieved in Mixed Logit analyses, showing that at least part of the heterogeneity retrieved in such models is in fact scale heterogeneity, i.e. variation in absolute rather than relative sensitivities. In the present paper, the authors combine these two approaches. Specifically, they hypothesize that differences across respondents in survey engagement, understanding or attention causes differences in response quality, expressed as scale heterogeneity. The authors model this through a random scale approach that interacts with a latent variable model. Here, they find clear evidence of a link between this latent variable, model scale, and the response to various questions about survey realism and complexity. The resulting model is able to better represent the observed choices, while also leading to noticeable differences in the retrieved heterogeneity patterns.

This paper was sponsored by TRB committee ABJ40 Travel Survey Methods

01362476

12-2489

English

19p

2012

Transportation Research Board 91st Annual Meeting

Digital/other

Figures; References; Tables

Bias (Statistics); Choice models; Data quality; Logits; Random variables; Stated preferences; Surveys

Endogeneity; Latent variables; Respondents (Surveys)

Planning and Forecasting; Research; Transportation (General); I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2012 Paper #12-2489

TRIS, TRB

Feb 8 2012 5:09PM