|Project Status Reports:|
From Proceedings of April 2-3, 1998 Workshop:
This project is developing a model of public preferences for forested wetland attributes in Rhode Island by integrating methods from environmental eco- nomics with guidance from conservation biology. The project’s objectives are to: (1) identify critical ecosys- tem attributes of forested wetlands, considering both the impact on residents’ quality of life and factors identified as important by conservation biologists; (2) develop a model of public preferences for alternative attributes of forested wetlands, using Rhode Island as a case study; and (3) estimate money-measures of economic value for forested wetland attributes by conducting a survey of the public and comparing survey responses based on hypothetical dollar costs to responses based on questions that require respondents to contribute real money.
The survey method will ask respondents to review descriptions of two or more parcels of land with wetland attributes and to choose a parcel, if any, for which the respondent would be willing to pay a specified price to guarantee some level of protection of ecological servi- ces. Some of these parcel descriptions will pertain to land that belongs to private landowners who have agreed to cooperate with the research.
Prior to the actual wetland survey, a review of conservation biological guidance has been completed for the selection of lands for priority preservation, as prac- ticed by private and public organizations in New England. Preliminary surveys are being developed to serve as extensive pretests of the format and presentation of choice questions involving either real or hypothetical monetary payments for wetland conservation. These preliminary surveys involve the use of a closely related good, the provision of water-quality monitoring services on freshwater bodies in Rhode Island.
Conservation biological guidelines used by state environmental management officials and nonprofit con- servation groups focus on criteria that include (but are not limited to) the role of a wetland in expanding exis- ting conservation reserves or in completing a connecting corridor between reserves; the relative rarity of the wet- land type; the size of the parcel (e.g., >10 ha.); the surrounding land-use matrix and potential impacts from external land uses; and species diversity. Focus group discussions reveal, anecdotally, that many Rhode Island residents consider similar factors, albeit in laymen’s terms, when attempting to identify whether a parcel deserves a high priority for conservation funding. Residents also consider the potential for public access to newly protected parcels, and they may give greater weight to the diversity of species that may be more visible (e.g., birds, mammals). These findings support the working assumption that respondents will have some preexisting experience with evaluating wetlands along criteria that parallel factors considered by conservation biologists. One preliminary survey involving water quality monitoring is complete (Spencer, Swallow, and Miller, Agricultural and Resource Economics Review, forthcoming April 1998). This experiment produced no statistically significant difference between the estimated value of water quality monitoring services based on real or hypothetical dollar payments. However, the hypo-thetical-dollar estimate did exceed the real-dollar esti- mate by a factor of four; statistical insignificance of the difference could be attributed to the wide standard error on hypothetical estimates (see Table 1). In this experiment, the hypothetical survey presented choice ques- tions in a format that paralleled the real money survey by including a hypothetical version of the details neces- sary in the real-money survey. Investigators are de- signing the next pretest to examine whether this addi- tional detail generated an unanticipated hypothetical bias that may account for the high standard errors in the hypothetical survey.
The last pretest survey is under way for spring of 1998. Various mechanisms will be evaluated to dis- courage free-riding in the real-money survey, including the use of “provision points” (or “funding targets” and “money-back guarantees.” The pretest is focused on using the discrete choice format because our focus group results suggest that this format focuses respon- dents’ attention on tradeoffs among choice attributes. The surveys will be conducted in a field format. These plans also allow for comparisons with hypothetical for- mats that parallel the real formats to varying degrees. Based on these comparisons, the survey concerning forested wetland attributes will be conducted using the hypothetical survey format that matches the real-money willingness-to-pay figures most closely.
Table 1. Willingness-to-pay estimates for the average respondent, based on Spencer, Swallow, and Miller (Agricultural and Resource Economics Review, forthcoming April 1998).
|Hypothetical WTP||Real-Money WTP |
|Pond A || $42.69|
|Pond B || $63.23 |
Note: Parentheses denote standard errors.
* Significant at P< 0.001 for a one-tailed test of H0: WTPk = 0 versus HA: WTPk > 0.
† Significant at P< 0.01 for a one-tailed test of H0: WTPB = WTPA versus HA: WTPB > WTPA.
From previous status report:
Objective of Research:
The overall objective of the research is to develop a quantitative model of public preferences for forested wetland attributes in southern New England by integrating methods from resource and environmental economics and experimental economics with knowledge from landscape ecology and conservation biology. Three main objectives of the research are: (1) to identify critical ecosystem attributes, of forested wetlands, that contribute to ecological quality and to the quality of life, (2) to develop a model of public preferences for alternative attributes of wetlands in southern New England, using Rhode Island as a case study, and (3) to estimate money-measures of value for wetland ecosystem attributes by a survey method which calibrates hypothetical dollar values to real-dollar values.
Objective (1) is partially complete (70%). The investigators have conducted an extensive review of the ecological and non-ecological factors considered in the land acquisition practices of various New England environmental organizations and agencies (such as The Audubon Society, The Nature Conservancy, and state level environmental protection agencies). The investigators, also, have conducted personal interviews with representatives from some of these organizations to learn what ecological factors (particularly in forested areas) interest their members and supporters. Preliminary work towards a methodology to complete Objectives (2) and (3) has begun in earnest. The investigators have developed and pre-tested a preliminary approach which adapts contingent choice survey questions to estimate real-money values. The pre-test, which elicited individual preferences for real water quality monitoring programs, illustrates the feasibility of accomplishing Objectives (2) and (3), as specified in this project. A paper based on our preliminary approach has been submitted to a peer reviewed journal, Agricultural and Resource Economics Review.
Accomplishments and Research Results:
To date, several accomplishments and research results have been reached. First, as mentioned above, several activities involved in identifying ecosystem attributes of forests (and particularly forested wetlands) which contribute to environmental quality and the quality of life have been accomplished. A review of the land acquisition priorities of various environmental organizations and interviews with some of their representatives indicate that the following forest attributes are important: richness and uniqueness of species inhabiting the forest, accessibility of forest to public, potential for educational uses, location to water bodies, uniqueness of ecosystem functions, size of parcel, characteristics of neighboring land, and adjacency to sanctuaries and other protected land. Other important concerns which have been identified are: preservation of rare ecosystems (such as Cedar Swamps), linking habitats and large protected areas, and protection of many species and large areas of ecological landscape. These results, in conjunction with planned focus groups made-up of Rhode Island residents, will complete Objective 1 and lead to the development of contingent valuation surveys which will elicit public preferences and willingness-to-pay for various attributes of forested wetlands.
Another important accomplishment is the development and pre-test of a preliminary approach to compare hypothetical and real-money values of environmental resources elicited in a contingent choice survey format. The preliminary approach used a split-sample design wherein different samples of respondents (consisting of college students from U.R.I.) answered either a hypothetical or a real-money survey which elicited their preferences for water quality monitoring programs. In the real-money surveys, respondents had a real opportunity (conditional on reaching a group total contribution) to add one or two ponds to a water quality monitoring program coordinated by staff at U.R.I. (Cooperative Extension, U.S.A.). The results of the preliminary study suggest that hypothetical willingness-to-pay (WTP) exceeds real WTP, but this may still reflect the free-riding problem (rather than a flaw in the hypothetical survey) or the result may reflect the nature and magnitude of value for the good being offered. The preliminary
study also found that (i) the specified purpose of monitoring and (ii) certain socioeconomic characteristics of the respondents significantly affect a respondent's decision to support volunteer water quality monitoring.
Spencer, Michael A., Stephen K. Swallow, and Christopher J. Miller (1997). "Valuing Water Quality Monitoring: An Economic Experiment Involving Hypothetical and Real Payments." Under review at Agricultural and Resource Economics Review.
Planned future activities are: (1) complete focus groups on public opinions concerning forest conservation, (2) pre-test a mail/field version of our hypothetical and real-money surveys, (3) complete survey design for forested wetlands case, (4) conduct forested wetland survey, (5) analyze data, and (6) prepare papers/presentations and write report.
For the year 1999
Objective: The project's objectives are to: (1) identify critical ecosystem attributes, of forested wetlands, that contribute to ecological quality and to the quality of life; (2) develop a model of public preferences for alternative attributes of wetlands in southern New England, using Rhode Island as a case study; and (3) estimate money-measures of value for wetland ecosystem attributes by a survey method which calibrates hypothetical-dollar values to real-dollar values.
To date, wetland attributes identified as important to public preferences for wetland conservation included: acreage of a wetland; type of land uses surrounding the wetland (wooded, residential, or farm); role of a wetland parcel in a conservation policy (relative to its role in expanding an existing conservation area, connecting two conservation areas, or creating a new but separate conservation area); expectation of the qualitative level of wildlife diversity likely supported by the parcel (low, medium, high); sustainability of the wildlife habitat; location relative to roads; potential for public access; and monetary cost, to a resident's household, necessary to implement a conservation agreement with the landowner.
The research design calls for the conduct of a two basic types of surveys. Both types of surveys will ask respondents to review descriptions of two wetland parcels, labeled Parcel A and Parcel B. Then respondents will be asked to state their willingness to pay for conservation on one of the parcels or to state that they are unwilling to pay specified costs for conservation of either parcel. In one version of the survey, respondents provide only their statement concerning their willingness or unwillingness to pay for conservation of a parcel. In the second version of the survey, respondents are asked to back up their stated willingness to pay with a real check or money order for the specified cost of conservation on any Parcel they choose (if they choose to a Parcel). In this second survey, all parcels descriptions will be matched with actual wetland parcels for which the landowner has agreed to enter a contract to forego their development rights if the group of survey respondents pay a specified amount (pre-determined by the researchers). Two landowners in Rhode Island have agreed to allow their wetland parcels to be used in this research.
The outcome of this project will allow a comparison of differences between estimated willingness to pay for wetland conservation (development-rights contracts) based on the two types of surveys (one involving only stated willingness to pay, and the second involving a request to actually pay the amount stated). This research will generally add to literature identifying differences between stated willingness to pay and actual dollar payments. In addition, the research will allow an investigation of differences in willingness to pay for different attributes of wetland parcels, allowing an evaluation of tradeoffs among parcel attributes. Also, alternative versions of the two surveys will allow a comparison of effects associated with how the willingness to pay questions are presented. These comparisons will contribute to understanding the potential strengths and weaknesses of stated preference valuation for policy decisions. Furthermore, the demonstration of the two-survey method (stated preference versus real-money) can illustrate the potential for surveys in which statistical modeling can establish a means to adjust "hypothetical" (or stated) willingness to pay to a lower bound willingness to pay established by the real-money component of the survey. This real-money estimate is a lower bound because it is unlikely that real-money surveys can mitigate for all strategic reasons that respondents might have for understating their willingness to pay when real money is required.
Future Activities: During the forthcoming reporting period, year 2000, the investigators expect to complete the survey development (formatting and printing), implement the mail survey as described above, collect and code responses, and develop appropriate statistical analyses. Preliminary statistical results are anticipated for fall, 2000, with completion of the project currently scheduled for December 2000.
Publications and Presentations: Total Count: 4
Spencer MA, Swallow SK, Miller CJ. Valuing water quality monitoring: an economic experiment involving hypothetical and real payments. Agricultural and Resource Economics Review 1998;26(1):28-42.
Swallow SK. Economic value of habitat conservation through open space preservation in Richmond, Rhode Island. In: Proceedings of Challenges & Opportunities Facing Rhode Island's Biodiversity: The Science Behind the Issues. Fifth Annual Conference of the Rhode Island Natural History Survey, Community College of Rhode Island, Lincoln, RI, March 12, 1999 (abstracts).
Swallow SK. Public preferences for open space preservation. Presented at Rhode Island's Critical Lands Workshop, Sponsored by URI Cooperative Extension, URI Alton Jones Conference Center, West Greenwich, RI, July 17, 1998.
Swallow SK. The value of open space preservation, or the economic loss from open space development in Richmond, Rhode Island. Presented at the Seventh International Symposium on Society and Resource Management, Columbia, MO, May 27-31, 1998.
Supplemental Keywords: contingent valuation, nonmarket valuation, choice experiments, contingent choice/valuation, real environmental goods, hypothetical choices, real choices, calibration. , Economic, Social, & Behavioral Science Research Program, RFA, Scientific Discipline, Ecology and Ecosystems, Economics & Decision Making, Social Science, decision-making, biodiversity option values, community involvement, compensation, conservation, contingent valuation, cost effectiveness, decision analysis, economic incentives, ecosystem valuation, environmental assets, environmental values, forested wetlands, landscape ecology, policy analysis, preference formation, psychological attitudes, public policy, public values, social psychology, stakeholder, standards of value, stated preference, surveys, valuation, valuing environmental quality
The objectives of this research project were to: (1) identify critical ecosystem attributes of forested wetlands that contribute to ecological quality and to the quality of life; (2) develop a model of public preferences for alternative attributes of wetlands in southern New England using Rhode Island as a case study; and (3) estimate money-measures of value for wetland ecosystem attributes by a survey method that calibrates hypothetical-dollar values to real-dollar values.
This project developed a list of wetland attributes that may be significant for evaluation of public preferences. This list ranged from focus groups to a review of the conservation biology literature. The attributes listed below do not include all attributes considered important by applied ecologists, because the objective focuses on attributes of concern in public preference analysis. These attributes included: (1) acreage of a wetland; (2) type of land uses surrounding the wetland (wooded, residential, or farm); (3) role of a wetland parcel in a conservation policy (relative to its role in expanding an existing conservation area, connecting two conservation areas, or creating a new but separate conservation area); (4) expectation of the qualitative level of wildlife diversity likely supported by the parcel (low, medium, high); (5) sustainability of the wildlife habitat; (6) location relative to roads; (7) potential for public access; and (8) monetary cost to a resident's household, which is necessary to implement a conservation agreement with the landowner.
The project was designed to implement mail surveys for stated preference assessments of the public's value toward conserving a parcel of wooded wetlands. The survey design presented respondents with choices between two parcels described by the attributes above. Respondents could state their preference to preserve parcel A, parcel B, or their preference to retain the implied costs and forego both parcels. If they forego both parcels, then they are preserving neither of them. These survey questions were implemented in two forms. In the first, all parcel choices involved hypothetical land parcels, and the respondent's cost also was hypothetical. In the second form, the parcel descriptions matched real-land parcels and respondents were told that they would need to write a check for "their cost" to demonstrate that they truly favored land conservation with regard to these costs. This approach established a data set in which responses to hypothetical questions could be analyzed in parallel with real-money questions. This analysis would identify departures in their willingness-to-pay (WTP) or environmental value estimates from the two types of questions.
The study established conservation contracts with two landowners who would permit the investigators (through the University of Rhode Island) to hold development rights for their land for a 10-year period. Wetland parcels under these conservation contracts constituted the parcels described in questions involving real-money. Respondents were told that conservation of a parcel meant the landowner would forego the right to develop his/her land for 10 years. Thus, the WTP that measures from both hypothetical and real-money questions focused on the value of placing a parcel under a 10-year contract.
Survey responses were analyzed using econometrics for discrete-response data. The statistical model assumes respondents identified the choice among parcel A, parcel B, or neither parcel, according to their preferences. The model estimates the probability that a particular parcel (or the neither choice) would be identified by the respondent as most preferred.
Several versions of the survey were designed to allow researchers to compare the effects associated with various aspects of how the survey presents real-money questions. One of the surveys presented respondents with a single-choice question involving real-money, while a second version included a hypothetical-choice question followed by an independent, real-money choice question. A third version of the survey presented two hypothetical-choice questions. These three versions of the survey allow several comparisons.
First, we have performed an analysis that compared stated-preference models estimated using data from different hypothetical questions. A general preference model was estimated, allowing each wetland attribute to carry a different effect on the likelihood that a respondent chose a particular wetland parcel for conservation. These effects could either be positive or negative, and it is denoted as a "marginal utility" of the attribute.
In this analysis, the hypothetical question that preceded the real-money question in one survey version was modeled in comparison to the hypothetical questions presented in the survey version that did not involve real-money. This comparison focuses on the respondents' reaction to the prospect of a real-money choice, but still uses hypothetical questions. The results suggest that the prospect of a real-money choice did not affect the marginal utilities (or relative marginal utilities) estimated for most wetland attributes. In particular, the marginal utility associated with most physical attributes of the wetland were not affected in a statistically significant manner, and the marginal utility of the cost attribute also was not affected. However, while not statistically different at a significant level, the marginal utility of the cost attribute from the hypothetical question in the real-money survey was about 60 percent larger in magnitude than its counterpart estimated from the hypothetical-only survey. This difference is important to note, despite the lack of statistical significance, because the respondents tended to react more negatively to a hypothetical cost question, prior to a real-money question.
However, while the marginal utility estimated for most wetland attributes was not affected by the prospect of a real-money choice question, there are 2 out of 13 exceptions. From the hypothetical question in the real-money survey, the marginal utility of conserving a wetland located in a wooded landscape, rather than in a farm or residential landscape, was positive and highly significant statistically (at the 1 percent level). Its counterpart from the hypothetical-only survey was negative, but not statistically significant at any conventional level. More surprisingly, the respondents' preference with respect to public access changed; indeed, the marginal utility reversed between the two versions of the hypothetical questions. In the hypothetical-only questions, respondents indicated a positive and strongly significant marginal utility for wetland parcels, allowing full public access. In the hypothetical question drawn from the real money survey, this marginal utility was negative, of similar magnitude, and still highly statistically significant.
These results raise the possibility that survey respondents may alter their stated preferences for some attributes of an environmental good, depending on whether the question is related to the prospect of a real-money choice. The results suggest that a preference reversal may occur with respect to some non-monetary attributes; this reversal is associated with changes in presentation prior to a real-money question. These results cast substantial doubt that only the prospect of paying actual money is relevant to departures between estimated WTP and actual WTP, as used for estimation of economic benefits from environmental goods. Even within a hypothetical question, respondents may alter their preferences by a substantial amount for a particular non-monetary, physical attribute of an environmental good.
The second comparison also was analyzed using the survey versions. The project compared the stated preference models that were estimated, based on the real-money questions in the two versions of the survey involving real money. Results indicate that the stated-preference model for the real-money survey questions was not affected by the presence of a hypothetical question (at least not in a statistically significant manner). This result would not be surprising, except that a contrary result was found for the hypothetical survey questions (as discussed above).
The final comparison involved evaluating the differences between real-money and hypothetical WTP in these survey versions. Existing results suggest a statistical difference between the hypothetical and real-money WTP, due to differences in the marginal utility of cost in these questions. It appears that a factor of two to four is observed in the marginal utility of cost between hypothetical and real-money questions. However, this conclusion cannot be drawn too broadly, because the hypothetical questions have proved to be sensitive to the prospect of a real-money choice. Further research clearly is necessary to help identify the factors causing departures in real and hypothetical WTP estimates. These factors may include shifts in preferences that may or may not be associated with standard economic principles, and factors associated with motivations for hypothetical bias as well as free-riding.
A Note on Presentation of Real-Money Questions. Two issues arose in designing the real-money survey questions. First, the project drew on methods in experimental economics where researchers have tested mechanisms that reduce the incentive of individuals to "free ride," or benefit from the financial contributions of others who help pay for an environmental good, such as wetland conservation. In preliminary research for this project, data obtained concerning WTP to monitor water quality in Rhode Island ponds showed that the real-money WTP of respondents and the difference between hypothetical WTP and real-money WTP depended upon how the provider of the environmental good (e.g., the conservation agent) utilized funds collected over and above the minimum needed to provide the good. Uncertainty played a role, but the primary factor affecting these WTP differences was whether respondents expected to receive a rebate of "their share" of any excess funds collected. These mechanisms were used in presenting the real-money questions within the wetland survey above.
The second issue concerned development of the real-money survey as a mail survey. It should be noted that substantial steps were needed to help respondents understand that the money collected would only be used for conservation of a specific wetland parcel (that matched the description given in the survey) and that excess contributions would be refunded to the respondent/contributor. These steps included explicit statements in the cover letter and in the survey questionnaire. However, despite these efforts, a substantial number of real-money survey respondents expressed concern that the survey was just another typical fundraiser. Response rates to the real-money survey were about 30 to 39 percent, while response rates to the hypothetical-only surveys were 39 to 54 percent, depending on the survey version and the Rhode Island town targeted in the survey. These different response rates suggest that the real-money survey may have caused respondents to react in ways not involved in the typical hypothetical, contingent valuation survey. Further research is suggested to understand the implications of this issue.
|Publications and Presentations: Total Count: 13|
|Journal Article||Whinstanley NL, Swallow SK. Are stated preferences invariant to the prospect of real-money questions? Journal of Environmental Economics and Management (submitted, 2002). ||not available |
|Journal Article||Spencer MA, Swallow SK, Shogren JF, List JA. Proportional rebate, random full-rebates, and winner-take-all rules in providing a threshold public good. Journal of Public Economics (in review, 2001). ||not available |
|Journal Article||Spencer MA, Swallow SK, Miller CJ. Valuing water quality monitoring: an economic experiment involving hypothetical and real payments. Agricultural and Resource Economics Review 1998;26(1):28-42. ||not available |
|Presentation||Whinstanley NL, Swallow SK. Are stated preferences invariant to the prospect of real-money choice? Presented at the 2002 Annual Meeting of the American Agricultural Economics Association, Long Beach, CA, July 28-31, 2002. ||not available |
|Presentation||Poirier N, Swallow SK. Contingent valuation of salt marsh mitigation. Presented at the Annual Meeting of The Wildlife Society, Buffalo, NY, September 1998. ||not available |
|Presentation||Swallow SK. Economic value of habitat conservation through open space preservation in Richmond, Rhode Island. In: Proceedings of Challenges & Opportunities Facing Rhode Island's Biodiversity: The Science Behind the Issues. Fifth Annual Conference of the Rhode Island Natural History Survey, Community College of Rhode Island, Lincoln, RI, March 12, 1999 (abstracts). ||not available |
|Presentation||Swallow SK. Methods and applications for ecosystem valuation: a collage. Presented at the National Science Foundation/U.S. Environmental Protection Agency Workshop on Valuing and Managing Ecosystem Resources. Economic Research Supported by the National Science Foundation and the Environmental Protection Agency, Washington, DC, October 29, 1998. ||not available |
|Presentation||Swallow SK, Spencer MA, Whinstanley L. Progress toward comparing stated preference and real money contingent values. Presented at the U.S. Environmental Protection Agency Workshop on Stated Preference: What Do We Know? Where Do We Go? Washington, DC, October 12-13, 2000, 24 pp. ||not available |
|Presentation||Swallow SK. Public preferences for open space preservation. Presented at Rhode Island's Critical Lands Workshop, Sponsored by URI Cooperative Extension, URI Alton Jones Conference Center, West Greenwich, RI, July 17, 1998. ||not available |
|Presentation||Spencer MA, Swallow SK. Testing for differences in hypothetical and real willingness-to-pay under the discrete-choice and open-ended contingent valuation formats: some experimental tests using a real, deliverable, environmental public good. Presented at the Northeastern Agricultural and Resource Economics Association Annual Meeting, Harrisburg, PA, June 9-11, 2002. ||not available |
|Presentation||Swallow SK. The value of open space preservation, or the economic loss from open space development in Richmond, Rhode Island. Presented at the Seventh International Symposium on Society and Resource Management, Columbia, MO, May 27-31, 1998. ||not available |
|Proceedings||Swallow SK. Economic value of habitat conservation through open space preservation in Richmond, Rhode Island. In: Proceedings of the Challenges and Opportunities Facing Rhode Island's Biodiversity: The Science Behind the Issues (from the 5th Annual Conference of the Rhode Island Natural History Survey, Community College of Rhode Island), Lincoln, RI, March 12, 1999 (abstract). ||not available |
|Proceedings||Swallow SK, Spencer MA, Whinstanley L. Progress toward comparing stated preference and real money contingent values. In: Proceedings of the U.S. Environmental Protection Agency Workshop on Stated Preference: What Do We Know? Where Do We Go? Washington, DC, October 12-13, 2000, (abstract). ||not available |
Supplemental Keywords: contingent valuation, nonmarket valuation, choice experiments, contingent choice/valuation, real environmental goods, hypothetical choices, real choices, calibration, RFA, ecology and ecosystems, economics, decisionmaking, social science, biodiversity option values, community involvement, compensation, conservation, cost effectiveness, decision analysis, economic incentives, ecosystem valuation, environmental assets, environmental values, forested wetlands, landscape ecology, policy analysis, preference formation, psychological attitudes, public policy, public values, social psychology, stakeholder, standards-of-value, stated preference, surveys, valuation, valuing environmental quality, Economic, Social, and Behavioral Science Research Program. , Economic, Social, & Behavioral Science Research Program, RFA, Scientific Discipline, Ecology and Ecosystems, Economics & Decision Making, Social Science, decision-making, biodiversity option values, community involvement, compensation, conservation, contingent valuation, cost effectiveness, decision analysis, economic incentives, ecosystem valuation, environmental assets, environmental values, forested wetlands, landscape ecology, policy analysis, preference formation, psychological attitudes, public policy, public values, social psychology, stakeholder, standards of value, stated preference, surveys, valuation, valuing environmental quality