Preferences with and without prices - does the price attribute affect behavior in stated preference surveys?

The experimental as well as the non-market valuation literature include several examples of how an introduced price can affect behavior in otherwise not expected ways. It has become standard to include a price vector as an attribute in choice experiments, something that enables us to estimate a marginal willingness to pay for other attributes. We test the impact on preferences by an inclusion of a price in a choice experiment. Preferences are affected, as might be expected. However, also the relative ranking of individual attributes is affected.