A joint investigation of public support and public values: case of instream flows in New Mexico

Instream flow can be defined as the flow of water in its natural channels without diversion. Alone among the western US states, New Mexico (NM) fails to provide any mechanism for the protection of instream flows and has a long history of political resistance to any change in the status quo. Using the combined results from two statewide telephone surveys, this study jointly investigates stated voting preferences for a proposed institutional change and stated valuation preferences for minimum instream how protection. The contingent valuation (CV) question uses a dichotomous choice (DC) elicitation format and a voluntary contribution trust fund payment vehicle. Results show a highly significant positive correlation between expressed voting preferences and expressed valuation preferences. Additionally, those individuals who respond YES to the voting question have an expected willingness to pay (WTP) of $80 with a 95% confidence interval (CI) that is always positive ($62-97), while those who respond NO to the voting question, have an expected WTP that is actually slightly negative (-$6) with a 95% CI containing zero (- $14-2). Taken together, these results provide evidence of construct validity. Estimation results are also shown to be temporally reliable across repeated samples. Thus, there is strong evidence of public support for instream flow protection and its associated nonmarket benefits. Such evidence helps to provide instream flow concerns with standing in future NM water policy debates. Prominent examples include explicitly defining 'beneficial use' and 'public welfare' to allow consideration of instream flow protection. (C) 1998 Elsevier Science B.V. All rights reserved.