Key points are not available for this paper at this time.
Richard T. Carson, Nicholas E. Flores, Kerry M. Martin, Jennifer L. Wright, Contingent Valuation and Revealed Preference Methodologies: Comparing the Estimates for Quasi-Public Goods, Land Economics, Vol. 72, No. 1 (Feb., 1996), pp. 80-99
Carson et al. (Thu,) studied this question.