Restricted versus unrestricted choice in labelled choice experiments: exploring the tradeoffs of expanding choice dimensions

The main objective of the study outlined in this paper was to examine how the inclusion of an additional labelled alternative, to provide respondents with more choice in a stated preference survey, impacted on choice complexity. The valuation context was to elicit preferences for improvements in the future condition of the Great Barrier Reef, Australia. A split sample experiment was implemented where one survey included four labelled alternatives: a status quo option and three specific policy management options (restricted choice). The other survey provided respondents with an unrestricted choice set by including a fifth alternative choice, labelled as “a combination of management options”. While the additional option improved opportunities to find an attractive choice profile, adding an extra alternative increased the complexity of the survey. The tradeoff between choice flexibility and complexity is examined in terms of changes in respondents’ choice behaviour and the performance of the different models. The results provide some evidence that adding a combination policy alternative did change the ways that respondents viewed tradeoffs, but that choice behaviour and subsequent value estimates were consistent across the two survey formats