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Planning for Demand Uncertainty in Integrated Water Resource Management

Author

Ray Quay

Journal

Journal at American Water Works Association 107:2, Volume 107, Number 2, February 2015, ISSN 2164-4535.

Because water supply and demand face equally uncertain futures, a strategy that considers their relationship and anticipates a range of possible future scenarios for these two fundamental aspects of water use might be the wisest approach for water resource managers.

Abstract

Ray Quay Sept 2012Uncertainty has been a driving factor in water resource planning for several decades, particularly in arid regions and in those with a high degree of interannual variability in precipitation.

In the last few decades, anticipatory governance has emerged as an approach for planning under conditions of high uncertainty.

In shifting from a predict-and-plan approach, water resource managers are anticipating a wide range of futures, developing response strategies, and adapting to anticipated changes as needed.

The uncertainty of water supply has been the primary focus of such efforts primarily because of the potential for long-term drought and climate change.

Until recently, water-demand estimating and forecasting have been viewed with greater certainty than water supply, with a focus on revenue projections, infrastructure capacity planning, and how demand can be reduced in the long term and quickly during drought.

However, water-demand estimating and forecasting have high levels of uncertainty, particularly in the longer time frame, and thus can also benefit from anticipatory governance. Integrated water resource planning is an approach that brings the uncertainty of water demand and supply into a common anticipatory governance framework.

Read and download the entire article at American Water Works Association.

Dave White Lecture at Global Institute for Water Security

Dave White was invited to speak as a distinguished lecturer at the University of Saskatchewan’s Breakthroughs in Water Security Research: The Global Institute for Water Security Distinguished Lecture Series on Wednesday, September 24, 2014.

Date: Wednesday, September 24, 2014
Time: 3:00pm in Arizona
Location: Neatby-Timlin Theatre, Arts 241, University of Saskatchewan
View the lecture: http://www.youtube.com/watch?v=TAwyv3KhAjQ

Lecture Title

Envisioning the future of water governance: Linking decision-maker preferences, simulation modelling and scenario analysis to inform sustainability transitions.”

Talk Abstract

DLSWhite Sept 24_225

The coupled effects of global climate change and population dynamics on water systems are widely considered to be among the greatest urban sustainability challenges facing humanity in the Anthropocene. Climate change impacts, including rising temperatures, changes in the amount and timing of local precipitation, and increased variability will very likely reduce renewable surface and groundwater supplies and diminish raw water quality, leading to widespread but uneven risks. Semiarid and arid regions will be particularly vulnerable. Meanwhile, the world’s urban population is projected to double in the next generation and much of this urban growth will occur in arid or semiarid environments. Climate impacts will amplify existing vulnerabilities in water-scare urban regions associated with inherent variability, cyclical drought, and extreme heat. Furthermore, the projected biophysical impacts of climate change are conditioned by and interact with land use changes, population dynamics, economic development, and water management decisions. Indeed, the non-climatic stressors on water resources may outweigh the climate impacts for some regions. Taken together, these interrelated pressures pose unprecedented challenges for urban sustainability. To address these challenges, there are growing number of scholars, policy-makers, and interest groups calling for transformational solutions to enable a transition towards urban water sustainability. An essential task for such transitions is to envision a sustainable future for water governance.

He will highlight recent research that utilizes a participatory, mixed-method approach, including survey questionnaire, scenario analysis, and simulation modeling, to construct distinct, coherent, plausible, and desirable governance scenarios of the Phoenix, Arizona USA region in 2030. Four scenarios provide stakeholders and policy makers with distinct options for future water governance regimes, while the approach integrates normative values and preferences with dynamic models to inform sustainable policy making. The first scenario, Technical Management for Megapolitan Development, based on the stakeholder survey, describes a future in which water experts negotiate and acquire more water so Phoenix can continue to grow. The second scenario, Citizen Councils Pursue Comprehensive Sustainability, was selected using the sustainability appraisal. This scenario describes a future where watershed-like councils use policy instruments to reduce water use as part of a comprehensive approach to sustainability that includes integrated policy making for water, energy, food, and urban planning. Experts Manage Limited Water for Unlimited Growth is the third scenario, selected using plausibility indications, and describes a future where water experts struggle to provide for a growing population without restricting water use or acquiring new water sources. Water governance reflects a classic “muddling through” approach. The final scenario, Collaborative Governance Prioritizes Local Water Security, selected using the water security governance analysis, is a future in which water is very central to decision making. In this scenario, committees of water managers, scientists and citizens collaborate to secure water and reduce consumption to ensure the long-term viability of the metropolitan region.

Each of the four scenarios was input into WaterSim 5.0 to determine their systemic impacts under different climate scenarios. The suite of models resulted in 270 separate model runs for the 75 year simulation period for each of the 33 water utilities and the four constructed synthetic scenarios plus one base scenario.

Our approach then allows for normative scenarios to interface with a dynamic simulation model, which during stakeholder engagement activities can provide feedback to participants on the impacts of their priorities, particularly on the availability of surface and groundwater for future generations and the distribution of burdens and benefits of water and water governance. Stakeholders can then modify or dictate preconditions for their priorities and, if necessary, select new scenarios. This type of iteration and feedback with differing levels of stakeholder involvement is critical in transdisciplinary research generally and for participatory scenarios that inform transitions in particular.

The scenarios in this study can be considered boundary objects, which allow for knowledge exchange between different actors related to their opinions, values, and preferences regarding all or parts of the water system. In this capacity, the scenarios present different water governance regimes with different power arrangements in a way that is comprehensible to broad audiences. For the Phoenix region, the scenarios can also facilitate conversations with other regions about water governance. Bounding the governance regime to the Phoenix region is a necessity of the scenario construction process that does not necessarily reflect the governance or hydrological reality. In the future, Phoenix will be negotiating for water with other state and regional actors, particularly those with rights to the Colorado River. By selecting a scenario to guide transition activities, Phoenix will have a boundary object with which to communicate its priorities to its partners on the Colorado River. Such efforts could contribute to further coordination of sustainable water governance across the Southwest.

New DCDC Publication

Assessing the sustainability of water governance systems: the sustainability wheel

Published online in the Journal of Environmental Planning and Management on July 11, 2014.

Authors

Flurina Schneider (a,b,e), Mariano Bonriposi (d), Olivier Graefe (c), Karl Herwega (a), Christine Homewood (c), Matthias Huss (c), Martina Kauzlaric (b), Hanspeter Liniger (a), Emmanuel Rey (b), Emmanuel Reynard (d), Stephan Rist (a), Bruno Schädler (b) & Rolf Weingartner (b)

Affiliations
a Centre for Development and Environment, University of Bern, Bern, Switzerland
b Department of Geography and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
c Geography Unit, Department of Geosciences, University of Fribourg, Fribourg, Switzerland
d Institute of Geography and Sustainability, University of Lausanne, Géopolis, Lausanne, Switzerland
e Decision Center for a Desert City, Julie Ann Wrigley Global Institute of Sustainability, Arizona State University, Tempe, AZ, USA

Flurina Schneider is a visiting scholar at Arizona State University, where she is affiliated with the School of Flurina SchneiderSustainability and Decision Center for a Desert City of the Julie Ann Wrigley Global Institute of Sustainability. She holds a PhD in human geography from the University of Bern, Switzerland. Schneider has conducted research on sustainable governance of water and land in Switzerland, Germany and Chile, focusing on multiple stakeholders’ perspectives and values, processes of transdisciplinary knowledge, co-creation through social learning and network building, as well as on issues of power and social justice.

Dr. Schneider is currently the scientific coordinator of the MontanAqua project, which develops strategies for moving towards more sustainable management of water resources in the Alps (Swiss National Science Foundation, Sustainable water management (NRP61)). Within this program, she also has the lead role in two synthesis projects concerning the development of principles of sustainable water use in Switzerland as well as the analysis of potentials and limitations of transdisciplinary knowledge production in research projects of the NFP61.

Abstract

We present and test a conceptual and methodological approach for interdisciplinary sustainability assessments of water governance systems based on what we call the sustainability wheel. The approach combines transparent identification of sustainability principles, their regional contextualization through sub-principles (indicators), and the scoring of these indicators through deliberative dialogue within an interdisciplinary team of researchers, taking into account their various qualitative and quantitative research results. The approach was applied to a sustainability assessment of a complex water governance system in the Swiss Alps. We conclude that the applied approach is advantageous for structuring complex and heterogeneous knowledge, gaining a holistic and comprehensive perspective on water sustainability, and communicating this perspective to stakeholders.

Introduction

In Switzerland, as in many other parts of the world, there is increasing concern that water shortage problems might become more frequent. Consequently, many research and policy efforts focus on issues of more sustainable water governance. However, there are few holistic approaches, which evaluate the sustainability of water governance systems based on comprehensive, interdisciplinary assessments (Reed and Kasprzyk 2009; Wiek and Larson 2012). Most frameworks emphasize singular aspects such as quality and supply of freshwater resources (Kondratyev et al. 2002), infrastructure, adaptive capacity (Hill 2013), or social learning (Pahl-Wostl 2006; Pahl-Wostl et al. 2007). Moreover, studies that investigate the sustainability of water governance systems from holistic perspectives (Larson, Wiek, and Withycombe Keeler 2013) primarily focus on the present situation without in-depth assessments of possible future developments.

A holistic framework for the analysis of sustainable water governance systems is proposed by Wiek and Larson (2012). Their framework combines a systemic understanding of the water governance system and its evaluation through a set of sustainability principles. They stress the importance of justifying the normative claims in the system analysis with a transparent set of value laden sustainability principles.

Another approach that is commonly chosen to evaluate water governance sustainability from an interdisciplinary perspective is the application of indicators (Sullivan and Meigh 2007; Valenzuela Montes and Matarán Ruiz 2008; Ioris, Hunter, and Walker 2008; Babel et al. 2011; Lachavanne and Juge 2009 ). The great advantage of indicators is that they provide a reasonably simple tool to combine biophysical and socioeconomic information (Sullivan and Meigh 2007), and allow the reflection and communication of complex ideas by condensing their multifaceted nature into a manageable amount of meaningful information (Babel et al. 2011), yielding good learning opportunities (Ioris, Hunter, and Walker 2008). However, they also have limitations; quantitative indicators often require (over)simplifying complex and dynamic water governance systems (Ioris, Hunter, and Walker 2008). Consequently, aspects that are hard to measure, or hard to quantify, such as informal governance practices, are neglected (e.g. Lachavanne and Juge 2009 ). Furthermore, gaps in data often limit the applicability and information value for different case study areas.

Schneider Figure 3Against this background, our goal is to present a conceptual and methodological approach for an interdisciplinary sustainability assessment for water governance systems – based on what we call the sustainability wheel – and its application in the Crans-Montana-Sierre region of Switzerland, the case study area of the MontanAqua project (Weingartner et al. 2010). For this purpose, we took the basic ideas of the two approaches described above and combined them in a way that would allow the evaluation of the water governance system through a comprehensive, interdisciplinary assessment.

In this article, we use the term water governance system in a broad sense. Water governance systems are understood to include social practices and institutions, as well as biophysical aspects and processes. When using the term water resource systems, we only refer to the biophysical aspects and processes.

Download the entire article.

Should sustainability and resilience be combined or remain distinct pursuits?

A recent publication in Ecology and Society by DCDC co-director, Chuck Redman, explores whether sustainability and resilience should be combined or remain distinct pursuits.

Author

Charles L. Redman, DCDC co-director, Professor and Founding Director, School of Sustainability, Arizona State University

Abstract

Chuck RedmanIt has become common for sustainability science and resilience theory to be considered as complementary approaches. Occasionally the terms have been used interchangeably. Although these two approaches share some working principles and objectives, they also are based on some distinct assumptions about the operation of systems and how we can best guide these systems into the future. Each approach would benefit from some scholars keeping sustainability science and resilience theory separate and focusing on further developing their distinctiveness and other scholars continuing to explore them in combination. Three areas of research in which following different procedures might be beneficial are whether to prioritize outcomes or system dynamics, how best to take advantage of community input, and increasing the use of knowledge of the past as a laboratory for potential innovations.

Conclusion

The history and archaeology of the past 10,000 years have shown countless examples of people, as individuals, small groups, and increasingly large organizational units, facing changing conditions, serious stresses, and unexpected shocks. Although the geographic scale of modern challenges appears to dwarf historical challenges, systemic shocks experienced by people in the past were just as daunting. Taking a big-picture perspective, people and societies have been amazingly successful in responding to challenges. By most objective measures, the human career to this point has been a great success!

If one takes a simple view of history, it is easy to argue that our society as it has developed will continue well into the future. This success has been achieved through adaptation and occasional transformations that, in virtually all cases, have exacerbated the divide between rich and poor and often led to further degradation of the environmental resources that both groups depend upon. Modest refinements or more efficient approaches to the challenges facing us will not reverse or alter this trajectory. Business as usual will perpetuate aspects of society we find socially undesirable and threaten the capacity of the Earth’s systems. We need to implement more sweeping, transformative changes in the way we interact with each other as well as with the surrounding built and natural environment.

If we need to transform our social-ecological systems to achieve a resilient and/or sustainable world, then we also need scientists to change their way of doing business. Unsurprisingly, personal and societal values influence scientists as they incorporate ethical ideals and approaches into their work. In my own research into future trajectories for urbanization, the ideas of sustainable cities and resilient cities have strong followings. In fact, it has been often suggested to me that for cities to be sustainable they must be resilient. Others argue that sustainable cities of the future will be “smart” cities (Harrison et al. 2010, Calabrese et al. 2011). Both Ecology and Society 19(2): 37 approaches have merits, and combining them may be the best option. However, a closer look at the mechanics proposed for smart cities, increasing energy and material efficiencies through highly interconnected information and decision systems, suggests an inflexibility and extreme hypercoherence that resilience theorists have often warned against (Holling and Gunderson 2002). Smart cities are unlikely to be more just cities, thus failing to achieve a key sustainability indicator. Urban planners and decision makers should assess the potential benefits to each approach, working through their implications in a holistic and consistent way. Toward that end, we must rigorously pursue adoption of distinct resilience and sustainability approaches, as well as combinations of the two, allowing each approach to contribute in ways that reflect its strengths.

View the entire article online at Ecology and Society.

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New DCDC Publication

Priorities in Residential Water Use: A Trade-Off Analysis

Authors

Edward Sadalla, Department of Psychology, Arizona State University
Anna Berlin, Department of Psychology, Arizona State University
Rebecca Neel, Department of Psychology, Arizona State University
Susan Ledlow, Department of Psychology, Arizona State University

Abstract

lmarquez_FreestonePark_fullA trade-off paradigm was used to examine priorities in residential water use. A total of 426 participants allocated either a small or large budget to various household water uses. A comparison of allocations across budget conditions revealed which water uses were regarded as most important, as well as the amount of water regarded as sufficient for each use. Further analyses focused on the perceived importance of outdoor water use, which accounts for the majority of the water used in residences. Data indicated that indoor uses, especially those related to health and sanitation, were consistently higher priorities for participants in this study. The finding that residents are more willing to curtail outdoor water use than indoor water use has important implications for behavior change campaigns. Individual difference variables of environmental orientation and duration of residence in the desert accounted for some of the variance in water choices.

Download the article from the Environment and Behavior at Sage Publications. Access may be limited.

New DCDC Publication

Water management decision makers’ evaluations of uncertainty in a decision support system: the case of WaterSim in the Decision Theater

Authors

Dave D. White, Decision Center for a Desert City, ASU
Amber Y. Wutich, School of Human Evolution and Social Change, ASU
Kelli L. Larson, School of Geographical Sciences and Urban Planning and the School of Sustainability, ASU
Tim Lant, U. S. Department of Health and Human Services

Abstract

DT_TimLant_296Model-based decision support systems are increasingly used to link knowledge to action for environmental decision making. How stakeholders perceive uncertainty in models and visualisations affects their perceptions of credibility, relevance and usability of these tools. This paper presents a case study of water decision makers’ evaluations of WaterSim, a dynamic water simulation model presented in an immersive decision theatre environment. Results reveal that decision makers’ understandings of uncertainty in their evaluations of decision support systems reflect both scientific and political discourse. We conclude with recommendations for design and evaluation of decision support systems that incorporate decision makers’ views.

Download the article from the Journal of Environmental Planning and Management

New DCDC Publication

Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

Published in Hydrology and Earth Systems Sciences, January 13, 2014.

Authors

Amber Wutich, School of Human Evolution and Social Change, ASU
A.C. White, School of Human Evolution and Social Change, ASU
Dave D. White, School of Community Resources and Development, ASU
Kelli L. Larson, School of Geographical Sciences and Urban Planning, ASU
Alexandra Brewis, School of Human Evolution and Social Change, ASU
Christopher Roberts, School of Human Evolution and Social Change, ASU

Abstract

Brazil damIn this study, we examine how development status and water scarcity shape people’s perceptions of “hard path” and “soft path” water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

Citation

Wutich, A., White, A. C., White, D. D., Larson, K. L., Brewis, A., & Roberts, C. (2014). Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions. Hydrol. Earth Syst. Sci., 18(1), 109-120. doi: 10.5194/hess-18-109-2014

Read the entire article at Hydrology and Earth Systems Sciences.

New DCDC Publication

Impact of urban form and design on mid-afternoon microclimate in Phoenix Local Climate Zones

Authors

Ariane Middel, Center for Integrated Solutions to Climate Challenges, Arizona State University

Kathrin Häb, Department of Computer Science, University of Kaiserslautern, Germany

Anthony J. Brazel, School of Geographical Sciences and Urban Planning, Arizona State University

Chris A. Martin, Science and Mathematics Faculty, School of Letters and Sciences, Arizona State University

Subhrajit Guhathakurta, Center for Geographic Information Systems, Georgia Institute of Technology

Abstract

Ariane Middel figureThis study investigates the impact of urban form and landscaping type on the mid-afternoon microclimate in semi-arid Phoenix, Arizona. The goal is to find effective urban form and design strategies to ameliorate temperatures during the summer months. We simulated near-ground air temperatures for typical residential neighborhoods in Phoenix using the three-dimensional microclimate model ENVI-met. The model was validated using weather observations from the North Desert Village (NDV) landscape experiment, located on the Arizona State University’s Polytechnic campus. The NDV is an ideal site to determine the model’s input parameters, since it is a controlled environment recreating three prevailing residential landscape types in the Phoenix metropolitan area (mesic, oasis, and xeric). After validation, we designed five neighborhoods with different urban forms that represent a realistic cross-section of typical residential neighborhoods in Phoenix. The scenarios follow the Local Climate Zone (LCZ) classification scheme after Stewart and Oke. We then combined the neighborhoods with three landscape designs and, using ENVI-met, simulated microclimate conditions for these neighborhoods for a typical summer day. Results were analyzed in terms of mid-afternoon air temperature distribution and variation, ventilation, surface temperatures, and shading. Findings show that advection is important for the distribution of withindesign temperatures and that spatial differences in cooling are strongly related to solar radiation and local shading patterns. In mid-afternoon, dense urban forms can create local cool islands. Our approach suggests that the LCZ concept is useful for planning and design purposes.

Citation

Ariane Middel, Kathrin Häb, Anthony J. Brazel, Chris A. Martin, Subhrajit Guhathakurta, Impact of urban form and design on mid-afternoon microclimate in Phoenix Local Climate Zones, Landscape and Urban Planning, Volume 122, February 2014, Pages 16-28, ISSN 0169-2046, http://dx.doi.org/10.1016/j.landurbplan.2013.11.004.

New DCDC Publication

Assessment of De Facto Wastewater Reuse across the U.S.: Trends between 1980 and 2008

Published

August 19, 2013 in Environmental Science and Technology, DOI: 10.1021/es402792s

Authors

Jacelyn Rice, School of Sustainable Engineering and the Built Environment and DCDC Graduate Research Assistant, ASU
Amber Wutich, School of Human Evolution and Social Change, ASU
Paul Westerhoff, School of Sustainable Engineering and the Built Environment, ASU

Abstract

De Facto Reuse RiceWutich WesterhoffDe facto wastewater reuse is the incidental presence of treated wastewater in a water supply source. In 1980 the EPA identified drinking water treatment plants (DWTPs) impacted by upstream wastewater treatment plant (WWTP) discharges and found the top 25 most impacted DWTPs contained between 2% and 16% wastewater discharges from upstream locations (i.e., de facto reuse) under average streamflow conditions. This study is the first to provide an update to the 1980 EPA analysis. An ArcGIS model of DWTPs and WWTPs across the U.S. was created to quantify de facto reuse for the top 25 cities in the 1980 EPA study. From 1980 to 2008, de facto reuse increased for 17 of the 25 DWTPs, as municipal flows upstream of the sites increased by 68%. Under low streamflow conditions, de facto reuse in DWTP supplies ranged from 7% to 100%, illustrating the importance of wastewater in sustainable water supplies. Case studies were performed on four cities to analyze the reasons for changes in de facto reuse over time. Three of the four sites have greater than 20% treated wastewater effluent within their drinking water source for streamflow less than the 25th percentile historic flow.

Read the entire article at Environmental Science and Technology.

New DCDC Publication

Quasi Experiments, Hedonic Models, and Estimating Trade-offs for Local Amenities

Authors

H. Allen Klaiber and V. Kerry Smith.

Journal

Land Economics, Volume 89, Number 3, August 2013

Abstract

This paper evaluates whether the property value capitalization effects measured with quasi-experimental methods offer reliable estimates of willingness to pay for changes in amenities. We propose the use of a market simulation as a robustness check. Two applications establish the method’s relevance. The first examines the conversion of land cover from desert to wet landscape. The second examines cleanup of hazardous waste sites. We find that even when quasi-experimental methods have access to ideal instruments, their performance in measuring general equilibrium willingness to pay cannot be assumed ideal. It needs to be evaluated considering the specific features of each application.

Introduction

Klaiber Smith Figure 2There is a fundamental distinction between estimating the effect of a policy that influences the value of a parcel on that land’s price and estimating what an individual would be willing to pay to obtain the policy. This issue is important to nearly all of the reduced form quasi-experimental (QE) and hedonic property value analyses conducted over the past decade. This distinction arises because the source of identifying information used to avoid biases in hedonic estimates that can arise from omitted variables and sorting behavior is not neutral to the economic interpretation of what is measured.1 Two approaches have been used to evaluate the empirical significance of this logical distinction in recovering estimates of economic trade-offs associated with a change in a nonmarket service. The first uses analytical models to describe the properties of these trade-off estimates, using the evaluation logic often associated with quasi experiments.2 The second approach uses simulation methods to evaluate the quantitative importance of distinguishing specific types of changes in site-specific amenities and [End Page 413] compares the evaluation logic to conventional cross-sectional hedonic methods.

The theoretical analysis by Kuminoff and Pope (2012) is an example of the first strategy. They adapt the Tinbergen-and-Jan-1959Tinbergen (1959)-Epple (1987) description of the features of a hedonic price function to describe a hedonic equilibrium. With this model they demonstrate that for an infinitesimal, exogenous change in a spatial attribute, conveyed with a house, the prechange and postchange marginal willingness to pay (MWTP) measures will be equal and correspond to the incremental price capitalization. However, in other situations the price differential associated with capitalization may not correspond to either the prechange or the postchange MWTP. In evaluating policies that are inherently nonmarginal, the close relationship between capitalization and willingness to pay (WTP) may not hold. In the current paper, we use simulation methods originating in the logic developed by Cropper, Deck, and McConnell (1988) and Kuminoff, Parameter, and Pope (2010) to provide a strategy for developing an understanding of this relationship as it arises in each specific type of application. An economic model, calibrated to a specific market, is used to simulate different hedonic equilibria and then to evaluate the performance of conventional cross-sectional hedonic models and methods based on the logic of program evaluation for estimating specific trade-offs people would make in response to changes in spatially varying amenities.

Our analysis complements the existing hedonic simulation papers and extends them to demonstrate how a market simulation can serve as a robustness check on the maintained assumptions of the evaluation logic when it is used to develop measures in property value applications of the trade-offs a person would make to secure more of a desirable amenity. For small changes, analysts have interpreted these measures as point estimates of the MWTP. For large, discrete changes associated with some applications of the evaluation framework, the appropriate interpretation of these measures is a topic of debate. Our analysis provides additional guidance on the interpretation of these measures. We focus on situations where the measure of interest is the general equilibrium willingness to pay (GE WTP) for changes in amenities, which is often the goal of policy analysis. We present two examples to illustrate the importance of a simulation check. Our findings in these examples imply that quasi experiments that are routinely a part of the evaluation logic can have large errors when their estimates of price capitalization are treated as estimates of WTP. We also find that the use of instruments with cross-sectional hedonic modeling can improve the quality of the estimates for the WTP for discrete changes in amenities. This is true even when the changes are large enough to induce re-sorting and result in a new hedonic price function. Finally, we find that the context for each application matters, so that general conclusions about robust strategies for estimating GE WTP do not follow; and therefore, it would be prudent to consider the use of similar simulations as a complement to empirical research on a case-by-case basis.

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