Nonmarket valuation of water quality in a rural transition economy in Turkey applying an a posteriori bid design

Abstract

[1] In this paper, we investigate the economic benefits associated with public investments in wastewater treatment in one of the special protected areas along Turkey's touristic Mediterranean coast, the Köycegiz-Dalyan watershed. The benefits, measured in terms of boatable, fishable, swimmable and drinkable water quality, are estimated using a public survey format following the contingent valuation (CV) method. The study presented here is the first of its kind in Turkey. The study's main objective is to assess public perception, understanding, and valuation of improved wastewater treatment facilities in the two largest population centers in the watershed, facing the same water pollution problems as a result of lack of appropriate wastewater treatment. We test the validity and reliability of the application of the CV methodology to this specific environmental problem in a rural transition economy and evaluate the transferability of the results within the watershed. In order to facilitate willingness to pay (WTP) value elicitation we apply a novel dichotomous choice procedure where bid design takes place a posteriori instead of a priori. The statistical efficiency of different bid vectors is evaluated in terms of the estimated welfare measures' mean square errors using Monte Carlo simulation. The robustness of bid function specification is analyzed through average WTP and standard deviation estimated using parametric and nonparametric methods.

Cost-Benefit Analysis of the Swiss National Policy on Reducing Micropollutants in Treated Wastewater

“…Other earlier work using SPs includes estimating the WTP for establishing a pharmaceutical disposal program in southern California, covering only one group of MPs . Several studies estimated the economic values of water quality improvements achieved by reduced sewer outflows or overflows. − However, they do not focus specifically on MPs and their uncertain effects.…”

Measuring willingness to pay to improve municipal water in southeast Anatolia, Turkey

“…Genius et al [2008] determined a value of approximately A10.64 per household for respondents residing in the Municipality of Rethymno. While the overall focus was different, the study of Tümay and Brouwer [2007] had many similarities to ours. Their study, conducted in the area of the Antalya Koycegiz-Dalyan water basins, focused on the evaluation of wastewater using three different bid price scenarios.…”

“…Such a result is also consistent with international findings [Edwards, 1988;Briscoe et al, 1990;Sun et al, 1992;Brox et al, 2003;Rosado et al, 2006;Shultz and Soliz, 2007;Genius and Tsagarakis, 2006;Genius et al, 2008] determined for high-quality drinking water. In a study conducted in the Koycegiz-Dalyan watershed of Antalya, Tümay and Brouwer [2007] also reported the positive impact of education on WTP. However, the effect was not statistically significant.…”

“…Their study, conducted in the area of the Antalya Koycegiz-Dalyan water basins, focused on the evaluation of wastewater using three different bid price scenarios. Tümay and Brouwer [2007] found that consumers were willing to pay 24.4 TL, 33.3 TL, and 26.2 TL for Dalyan, and 10.6 TL, 14.5 TL, and 11.6 TL for Koycegiz. In contrast to the above estimates using the logit model, their estimations obtained using the Turnbull model approximated relatively smaller values such as 3.4 TL, 3.5 TL, and 4.0 TL, respectively, for Dalyan; and 3 TL, 3.6 TL and 3.2 TL, respectively, for Koycegiz.…”

Horticultural Growers’ Willingness to Adopt Recycling of Irrigation Water

“…Thus, using percentages allows the costs to be realistic for different size operations. Percent cost increases, rather than absolute increases, have been used in other applications where respondents would find it difficult to respond to absolute cost amounts (see Bederli and Brouwer, 2007).…”