Practice and Required Sample Number of Payment Card Contingent Valuation Method in Case of Promotionof Increment of Tidal Flat and Shallow Water Area in Mikawa Bay

Abstract

Contingent Valuation Method (CVM) is a typical method for us to measure the benefit and/or cost of goods having no market, such as tidal flats and shallow water area. CVM has several types for gettinganswers. Among them, the referendum type is seemed having least biases in the estimation. But, the payment card type is rather preferred to the referendum type in business practices, because the referendum type requires many data for reliable estimation. Using the case of promotion of tidal flat andshallow water area in Mikawa Bay, the authors analyzed the statistical reliability of the payment card type CVM for the purpose of enhancing usability of the method.
The author estimated WTP median and compared the WTP median and its precision estimated by the density distribution curve with those by the cumulative distribution curve. Significant difference of WTP medians was not observed. There was, however, significant difference in the precisions of WTP median. Therefore, the author formulated an error rate function by the sample number in the case of using the density distribution curve.