The Benefits of Improvements in Coastal Water Quality: A Contingent Approach

摘要

Brest natural harbour was chosen by the European Community as a pilot site to research into improvements in coastal water quality. The depollution program will be financed by the Community, the French Government and the regional authorities. There are two problems that are a priority to be resolved: microbe contamination from urban sources and over-enrichment by nutrients from agricultural sources. This paper deals with the non-market value which local people give to water quality in the harbour. Our objectives are to improve the knowledge about the demand for natural assets in France, and, simultaneously, to prepare a cost-benefit analysis which will aid decision-making concerning the restoration of the harbour. In an on site survey carried out in summer 1993, we developed a contingent valuation for two goods: (1) improved water salubrity, and (2) preservation of the ecosystem against eutrophication. The corresponding willingness to pay (WTP) values were explained using Tobit models. Whatever the good, the WTP was seen to rise with revenue. However, whilst the WTP "salubrity" was affected by environmental sensibility and awareness of local pollution, it is education above all which affected the WTP "ecosystem". On the whole, residents accepted the exercise of contingent valuation and were willing to give important amounts (FF215 and FF 160 on average per household per year, respectively, for goods 1 and 2). The differences between the goods and the significance of the resulting WTPs are discussed.