Nancy E. Bockstael

Spatial landscape indices in a hedonic framework: an ecological economics analysis using GIS

Abstract This paper develops a spatial hedonic model to explain residential values in a region within a 30-mile radius of Washington DC. Hedonic models of housing or land values are commonplace, but are rarely estimated for non-urban problems and never using the type of spatial data (geographical information system or GIS) available to us. Our approach offers the potential for a richer model, one that allows for spatial heterogeneity in estimation, and one that ties residential land values to features of the landscape. Beyond the traditional variables to explain residential values, such as man-made and ecological features of the parcel and distance to cities and natural amenities, we also hypothesize that the value of a parcel in residential land use is affected by the pattern of surrounding land uses, not just specific features of point locations. We have also created and added these variables to the hedonic model by choosing an appropriate area around an observation, and calculating measures of percent open space, diversity, and fragmentation of land uses, measured at different scales around that observation. These indices have, for the most part, been significant in the models. By including two of the landscape indices developed by landscape ecologists, we have developed a model that explains land and housing values more completely, by capturing how individuals value the diversity and fragmentation of land uses around their homes.

Modeling Economics and Ecology: The Importance of a Spatial Perspective

Interdisciplinary work in environmental economics, and increasingly in certain areas of interest to agricultural economists, frequently involves us with essentially ecological problems. A few notable examples include nonpoint source pollution, water quality, biodiversity, and global climate change. As we take on these problems, we are being asked to look at the world through the lens of population (or community) and systems ecologists. Conflicts and frustration generally result and are usually put down to fundamental differences in philosophy, but may largely be due to differences in the modeling structure the two disciplines impose on the world.

Applying the Generalized-Moments Estimation Approach to Spatial Problems Involving Microlevel Data

The application of spatial econometrics techniques to microlevel data of firms or households is problematic because of potentially large sample sizes and more-complicated spatial weight matrices. This paper provides the first application to actual household-level data of a new generalized-moments (GM) estimation technique developed by Kelejian and Prucha. The results based on this method, which is computationally feasible for any size data set, track those generated from the more conventional maximum-likelihood approach. The GM approach is shown to have the added advantage of easily allowing estimation of a more flexible functional form for the spatial weight matrix.

The evolution of urban sprawl: Evidence of spatial heterogeneity and increasing land fragmentation

We investigate the dynamics and spatial distribution of land use fragmentation in a rapidly urbanizing region of the United States to test key propositions regarding the evolution of sprawl. Using selected pattern metrics and data from 1973 and 2000 for the state of Maryland, we find significant increases in developed and undeveloped land fragmentation but substantial spatial heterogeneity as well. Estimated fragmentation gradients that describe mean fragmentation as a function of distance from urban centers confirm the hypotheses that fragmentation rises and falls with distance and that the point of maximum fragmentation shifted outward over time. However, rather than outward increases in sprawl balanced by development infill, we find substantial and significant increases in mean fragmentation values along the entire urban–rural gradient. These findings are in contrast to the results of Burchfield et al. [Burchfield M, Overman HG, Puga D, Turner MA (2006) Q J Econ 121:587–633], who conclude that the extent of sprawl remained roughly unchanged in the Unites States between 1976 and 1992. As demonstrated here, both the data and pattern measure used in their study are systematically biased against recording low-density residential development, the very land use that we find is most strongly associated with fragmentation. Other results demonstrate the association between exurban growth and increasing fragmentation and the systematic variation of fragmentation with nonurban factors. In particular, proximity to the Chesapeake Bay is negatively associated with fragmentation, suggesting that an attraction effect associated with this natural amenity has concentrated development.

The Problem of Identifying Land Use Spillovers: Measuring the Effects of Open Space on Residential Property Values

development, such as traffic congestion and air pollution. Several willingness-to-pay studies have demonstrated the positive amenity value of open space (Halstead; Beasley, Workman, and Williams), but evidence of the value of open space from revealed preference methods--namely, from hedonic models--is limited and mixed. In this article, we consider the issue of estimating open space spillovers using a hedonic pricing model with residential property sales and offer an explanation for why the positive amenity value of open space effects, even if it exists, may not always be empirically detected. The estimation problems that we consider are ones of identification, which arise in a hedonic residential price model when the open space land is privately held and developable.1 Under these circumstances, land parcels counted as open space are part of the market for residential land and therefore subject to the same economic forces that determine a locations residential value.

Ecological economic modeling and valuation of ecosystems

Abstract We are attempting to integrate ecological and economic modeling and analysis in order to improve our understanding of regional systems, assess potential future impacts of various land-use, development, and agricultural policy options, and to better assess the value of ecological systems. Starting with an existing spatially articulated ecosystem model of the Patuxent River drainage basin in Maryland, we are adding modules to endogenize the agricultural components of the system (especially the impacts of agricultural practices and crop choice) and the process of land-use decision making. The integrated model will allow us to evaluate the indirect effects over long time horizons of current policy options. These effects are almost always ignored in partial analyses, although they may be very significant and may reverse many long-held assumptions and policy predictions. This paper is a progress report on this modeling effort, indicating our motivations, ideas, and plans for completion.

Measuring the Welfare Effects of Nutrition Information

Cost/benefit analysis justifies regulations altering the amount of health-related information presented to consumers. The current method of benefit analysis, the cost of avoided illness, is limited; it assumes the benefits of health-related information are adequately represented by changes in illnesses. The manuscript develops a benefit estimation method to measure the welfare impacts of providing nutrient information. Nutrient labeling significantly affects purchase behaviour but may not lead to increased consumption of health foods. Nutrient labeling may increase welfare without any change in health risk. Thus, the cost of avoided illness approach can underestimate the social benefits of providing nutrient information. Copyright 2001, Oxford University Press.

Measuring the Benefits of Improvements in Water Quality: The Chesapeake Bay

Federal, state, and local government agencies have joined forces in the ambitious and expensive task of improving the water quality of the Chesapeake Bay. Clean-up efforts will be devoted to three major problems: nutrient over enrichment, toxic substances, and the decline of submerged aquatic vegetation. Although the beneficiaries are ultimately human, criteria for judging the Bays water quality have been primarily biological and physical. This paper addresses the question of the human values from the Bay. How do people use the Bay and how much are they willing to pay for the changes in water quality that improve their use? With a variety of methods and data sources, we estimate the annual aggregate willingness to pay for a moderate improvement in the Chesapeake Bays water quality to be in the range of

Ecological Forecasting and the Urbanization of Stream Ecosystems: Challenges for Economists, Hydrologists, Geomorphologists, and Ecologists

10 to

A Random Utility Model for Sportfishing: Some Preliminary Results for Florida

100 million in 1984 dollars.