 Many of the value assignments used in cost-benefit analysis are based on estimates or measurements of (hypothetical) willingness to pay. Such estimates will give more influence to affluent people since they can pay more than others to have it their way. This can be corrected with income-based adjustments of the reported willingness to pay. However, there are considerable problems involved in the performance and interpretation of willingness-to-pay studies (Grüne-Yanoff 2009).