What are the consequences of ignoring attributes in choice experiments? Implications for ecosystem service valuation

- Attribute non-attendance is increasingly being seen as a serious problem for choice experiments.
- We analyse the impacts that partial attendance (i.e., a respondent 'sometimes' considers an attribute) have in CE.
- We find that partial attendance is a dominant response in CE.
- Models that account for partial attendance are statistically superior to models that do not.
- Our case study values the ecosystem service benefits associated with the UK Biodiversity Action Plan.

This paper investigates the sensitivity of choice experiment values 3AL for ecosystem services to 'attribute non-attendance'. We consider three cases of attendance, namely that people may always, sometimes, or never pay attention to a given attribute in making their choices. This allows a series of models to be estimated which addresses the following questions: To what extent do respondents ignore attributes in choice experiments? What is the impact of alternative strategies for dealing with attribute non-attendance? Can respondents reliably self-report non-attendance? Do respondents partially attend to attributes, and what are the implications of this? Our results show that allowing for the instance of 'sometimes attending' to attributes in making choices offers advantages over methods employed thus far in the literature.