In ecosystem services and landscape research, both monetary and non-monetary preference studies are applied to elicit values that people assign to landscapes. In this paper, we apply a split-sample approach to compare relative preferences for landscape attributes between a choice experiment with and an experiment without price attribute. Also, within the choice experiment with a price attribute, we examine the effect of non-attendance to the price attribute (i.e., ignoring the price) on landscape preferences. A comparison of the marginal rates of substitution of landscape attributes between the two experiments reveals a clear difference of preference patterns. In addition, 36% of the respondents in the monetary experiment ignored the price attribute. This group expressed similar preferences for landscape attribute as respondents in the non-monetary experiment. We also show that ignoring this type of non-attendance leads to a substantial upward bias in monetary value estimates. We conclude that adding a price attribute to choice experiments substantially affects trade-offs and choices made by respondents. Including a payment vehicle ensures that trade-offs between attributes are more pronounced, and that money has to be put where the mouth is. However, controlling for non-attendance appears crucial for obtaining accurate monetary value estimates.
van Zanten, B. T., Koetse, M. J., & Verburg, P. (2016). Economic Valuation at All Cost? The Role of the Price Attribute in a Landscape Preference Study. Ecosystem Services, 22B, 289-296. https://doi.org/10.1016/j.ecoser.2016.03.003