There is growing interest in incorporating both preference heterogeneity and scale heterogeneity in choice models, as a … incorporate scale heterogeneity in a generalised mixed logit (GMXL) model provides a way to accommodate these sources of influence …, observed and unobserved. The small but growing number of applications of the GMXL model have parameterized scale heterogeneity …

findings of Bradley and Daly (1994) who showed a significant drop in utility scale, i.e. an increase in error, as a respondent … in the literature are possibly overstated, with no clear decreasing trend in scale across choice tasks in any of our … studies. For the data sets tested, we find that accommodating any scale heterogeneity has little or no impact on substantive …