The criterion validity of willingness to pay methods: A systematic review and meta-analysis of the evidence.


Health Economics Research Group, Brunel University, Kingston Lane, Uxbridge, UB8 3PH, England, UK. Electronic address: [Email]


The contingent valuation (CV) method is used to estimate the willingness to pay (WTP) for services and products to inform cost benefit analyses (CBA). A long-standing criticism that stated WTP estimates may be poor indicators of actual WTP, calls into question their validity and the use of such estimates for welfare evaluation, especially in the health sector. Available evidence on the validity of CV studies so far is inconclusive. We systematically reviewed the literature to (1) synthesize the evidence on the criterion validity of WTP/willingness to accept (WTA), (2) undertake a meta-analysis, pooling evidence on the extent of variation between stated and actual WTP values and, (3) explore the reasons for the variation.


Contingent valuation,Criterion validity,External validity,Hypothetical values,Meta-analysis,Simulated market experiments,Systematic review,Willingness to pay,