MEASURING THE BENEFITS OF RIVER QUALITY IMPROVEMENT USING THE CONTINGENT VALUATION METHOD: THE CASE OF THE PING RIVER, CHIANG MAI, THAILAND

Rivers provide us with general life support, water supply, transportation, waste assimilation, and a wide array of recreation and tourism activities. However, due to undervaluation of the functions of rivers and river ecosystems, rivers of the world have been overexploited or degraded. To tackle the problem of undervaluation, this study measures the benefits of Ping River quality improvement using the contingent valuation method (CVM). The study estimates the lower-bound and higher-bound annual benefits gained by the residents of Chiang Mai District from the river quality improvement as 42,453,000 THB (1.25 million USD) and 102,835,317 THB (3 million USD), respectively. Moreover, in an attempt to explain the determinants of willingness to pay (WTP) statements, it was found that both behavioural and attitudinal factors affect WTP positively. The study also found distance decay, where WTP statements decreased with increased distance. And rather interestingly, male respondents tend to pay more than their female counterparts. Two other socioeconomic factors which affected WTP positively and significantly are education, partly because it can lead to a well paying and stable job, and normally raises the awareness of citizens towards environmental conservation, as well as income.