L'évaluation contingente : controverses et perspectives

Contingent valuation : controversial issues and perspectives In recent years, increasing public awareness of the detrimental effects of the economy on the environment has forced policymakers to assess the value of various public goods such as clean air and water, plant and animal species preservation, recreational sites and activities, scenic beauties, etc.... Over the last two decades, economists have developed and applied the method of contingent valuation to measure the value of various public goods. Recently a debate has raised among economists about the validity and rationality of the method. This debate pointed out some difficulties of contingent valuation studies. Measurement of the so called non use or preservation values has proved difficult. People may be sensitive to the warm-glow effect, and their answers may reflect more their willingness to pay for the environment in general than for the environmental good they are asked to value. Various solutions have been proposed to deal with these problems. We present and discuss them and we analyse the prominent elements of the current debate around the contingent valuation method. We develop the idea that currently used referendum methods have a too poor information content to provide reliable answers when the value of the good exhibits an important non use value component. We then explore the conjecture that the lack of imitations in the procedure may be a cause of unreliability of answers in contingent studies. Going back to the auction tradition of contingent valuation, we propose alternative ways of resolving some of the difficulties encountered in the practice of contingent valuation studies.L'intérêt pour les questions d'environnement conduit les pouvoirs publics à s'engager dans des politiques ambitieuses de préservation et de restauration des milieux naturels. La méthode d'évaluation contingente est actuellement un des outils privilégiés de la mesure des bénéfices de ces politiques. Pourtant cette méthode a fait récemment l'objet de vives controverses aux Etats-Unis remettant en cause sa pertinence et sa fiabilité. Elle est en particulier vulnérable à la présence de valeurs de non-usage importantes. L'objet de cet article est de présenter une synthèse de ces controverses, et de proposer différentes voies de recherche susceptibles de répondre aux difficultés rencontrées dans l'application de la méthode contingente.Amigues Jean-Pierre, Desaigues Brigitte, Vuong Quang H. L'évaluation contingente : controverses et perspectives. In: Cahiers d'Economie et sociologie rurales, N°39-40, 2e et 3e trimestres 1996. Économie de l'environnement. pp. 123-150