Value of time sensitivity to model specification

We compare values of time obtained with linear utility functions used in LOGIT and HIERARCHICAL LOGIT specifications of a nine-mode passenger choice model estimated with disaggregate data from Santiago, Chile, and find that they are sensitive to the specification used, unconvincingly high, and imply that the value of waiting time is a decreasing function of income. We then find that removing observations for individuals who face limiting values of price or service level yields partially improved results if the utility functions are still linear; but the most convincing results are obtained with explicitly nonlinear BOX-COX LOGIT specifications.