Fiabilité des résultats de méthode d'évaluation contingente et modes d'interrogation

This paper explores the reliability of estimates from contingent valuation method assessing the variability of contingent values collected by two modes of data collection: face-to-face interviewing or mail survey. We compare the results of two contingent valuation surveys on the willingness to pay for preserving groundwater quality in the Bievre-Liers Plain (Isere, France). Empirical results indicate that the mean willingness to pay estimated for each survey are significantly different