Testing geographical framing and substitution effects in spatial choice experiments

One of the main challenges in modelling spatial choices is the complexity resulting from the availability of multiple alternatives at different geographical scales. This study aims to test geographical framing and substitution effects in stated choice experiments by first increasing and subsequently reducing the geographical scale and associated set of choice alternatives in the experiment. Geographical framing effects are tested by comparing estimated choice models for differently sized choice sets. Testing these framing effects related to choice set size helps to inform decisions on choice set composition. The results indicate that changing the choice set size has little to no effect on preference parameters and estimated WTP values. However, the larger choice set is associated with higher error variance, suggesting higher choice task complexity.