The discrete-choice willingness-to-pay question format in health economics: should we adopt environmental guidelines?

The use of willingness to pay (WTP) in valuing the benefits of health care programs is increasing. Although such values have been derived using open-ended, bidding, or payment-card techniques, recently discrete-choice questionnaires have been advocated, particularly following the report of the National Oceanographic and Atmospheric Administration concerning the validity of using WTP to estimate environmental benefits. It is argued that discrete-choice questions offer a more realistic market, and will therefore lead to more valid responses and yield higher response rates through reduced mental demands. The author reviews these issues in a critical assessment of discrete-choice questions.