For the HCM method, the likelihood function for a given observation is the joint probability of observing the travel mode choice and the attitudinal indicators
that can be obtained as follows:
Using ordered attitudinal indicators
in a latent variable choice model: a study of the impact of security on rail travel behaviour.
All three PISA achievement scales and most of the attitudinal indicators
form a clear and parsimonious model (Figure 1).
Other researchers have argued that the information contained in attitudinal indicators should be assessed relative to that contained in financial indicators.
In both cases, results of less than one indicate that using the attitudinal indicator in the forecasting equation improves the out-of-sample forecast relative to the baseline equation.
Surveys of the Nielsen household panel reveal that members of the heavy drug group "strongly agree" or "agree" with the following attitudinal indicators