spectacle (1) marché (1) plomb (1) méthode (1) biens (1) Surveys (1) Euro (1) Contingent valuation (1) Value (1) Valuation (1) Surveys (1) Persons (1) Payment (1) Money (1) Human beings (1) Lead (1) Hypothesis (1) Experiments (1) Change (1) Valuation (1) Experiments (1)