OPEN SPACE ALLOCATION AND TRAVEL COSTS

The gain from dividing parks into smaller pieces to reduce travel costs is weighed against the loss in services the parks provide since they are smaller. The optimal number of parks is dependent on whether travel costs are concentrated in parts of the town.Resource /Energy Economics and Policy,

Amount and Spatial Distribution of Public Open Space to Maximize the Net Benefits from Urban Recreation

The spatial arrangement of public open spaces in communities has an important influence on the recreational net benefits from those public open spaces. A prime example of a public open space in communities where spatial arrangement is important is parks. From the perspective of maximizing the net benefits of recreation, there is a tradeoff between placing all the land for parks in a single park and making several parks to reduce the travel costs of households to the parks. If several parks are made, then the amount of land in each park is reduced, and the recreational net benefit of a trip to any of the parks is less. Since recreation is an important source of value from parks, an examination of an optimal spatial arrangement of parks for recreation in a community is of interest to community planners. The community is assumed to be a slice of a larger urban area or a small town since the housing structure and socioeconomic characteristics of the community is assumed homogeneous. The demand for recreation trips to parks is shifted by the socioeconomic characteristics of the population and the size of the parks. The size of the parks is the division of the number of parks into the total amount of land in parks. The price of a trip to a park is the cost of a round trip to the park. The consumer surplus of a trip to a park is the net benefit the person receives from the park. The amount of land for parks and number of parks to maximize the net benefits from recreation is determined from the model of the demand for trips to a park. Comparative static results suggest that the optimal amount of land, number of parks, and the size of the parks depend on the socioeconomic characteristics of the city. Cities with higher populations, more income, and more education should have more land in parks, more parks, and the parks should be smaller. Lower travel costs and prices of land should result in more land in parks and more parks, but there should be no influence on the park size. Data are collected from seventy cities on the amount of land, size, and number of parks. The distances between the parks, distances of the parks from downtown, and other variables relevant to the spatial distribution of parks are also obtained. Data on the socioeconomic characteristics of the population, travel costs, and the price of land are collected for the cities. The same data is collected for each of the one hundred and sixty nine zip codes associated with the seventy cities. These zip codes are spatially smaller and may better represent homogeneous communities. Three equations are estimated to learn the influence of the socioeconomic and travel cost features of a city on the spatial distribution of parks. The three equations are the estimation of the amount of land, the number and the size of parks. The results of the estimation for the amount of land in parks equation match the theoretical predictions, and the fit of the relationship is good. Population, population density, and land price have a significant influence on the amount of land in parks. A larger population makes a city create more land in parks while population density and the price of land makes a city reduce the amount of land. The results of the estimation for the number and size of parks are less clear. The results match the comparative static predictions loosely, and the fit of the equations is not good. These findings may reflect incorrect assumptions on the preferences of people for park size in the theoretical model, or the data that the preferences are supposed to represent are clouded with noise from government regulations, costly removal of parks, and other features of the complexity of urban spatial structure. Although recreation is significant component of the value households derive from parks, there has been little attention paid to determining the spatial arrangement of parks to maximize the net benefits. The theoretical results suggest that the amount of land and the spatial distribution of parks should be sensitive to the socioeconomic characteristics of a community. However, only the predicted signs of the socioeconomic characteristic on the amount of land in parks hold up empirically. The spatial distribution of land is more sensitive to institutional factors that probably make it necessary to have more data on parks to fully identify the relationship between the socioeconomic characteristics and the number and size of parks.Public Economics,

Development Patterns and the Recreation Value of Amenities

Public open spaces around and within urban areas have been increasingly developed due to greater population pressures. My paper investigates if land around public open spaces is likely to get developed faster since households are attracted to the recreation value as well as the environmental amenities of the public open space. There has been inadequate attention in the literature to the influence of the different sources of value of open space on housing prices. While views of open space are certainly an important source of value to households, public open space is also valued because households enjoy recreation at the open space. Adopting the monocentric city model, simulations examine how the different sources of value of public open space influence the developed area, rent gradient and the development density of an urban area. The monocentric city model has residents competing for housing around a single central business district (CBD) while developers choose the density of development from the expected prices of the homes at that location in the city. Simulations of the closed city model result in equilibrium rent gradients for land and the housing, a utility level, and a city boundary. By referencing the monocentric city model with two-dimensional coordinates, Wu and Plantinga (2003) are able to more spatially explicitly examine the influence of amenities on the equilibrium state of the city. Amenities are shown to generate leap-frog development, influence the developed area of the city, the population density, rent gradients and location of different income groups. Although different shapes and areas of amenities are examined in their paper, there is no investigation of the proper proximity of these amenities to each other. Several small amenities dispersed far apart from each other in the city may result in less total amount of developed land than if there is only a single large amenity. Another reason that the proximity of amenities to each other matters is that the net benefits from recreation are influenced by the spatial arrangement of the amenities. Consumer´s surplus from recreation trips to the amenity is the net benefit of the amenity, with the price of a recreation trip including the travel cost to the amenity. The travel costs from recreation at amenities depend on how widely dispersed the amenities are in the city. While several amenities located widely throughout a city lower the travel costs of recreation, the city tends to diffuse more too resulting in a larger developed area. On the other hand, a single centrally located amenity contracts the city resulting in a smaller developed area although the travel costs of recreation rise slightly. Simulations from the model collect information on the aggregate amount of recreation trips, recreational net benefits, and the developed area. More localized benefits of amenities like nice views and cleaner air have a stronger influence on housing prices and development densities than the less localized benefits of amenities like recreation. If the travel costs for recreation are low, then only the localized benefits of amenities influence housing prices and development densities. However, if the demand for recreation and the travel costs to reach the amenity is high, the benefits of recreation have the potential to influence the housing prices and development densities in that area of the city. There are several potential solutions to the problem of recreation benefits of the amenities leading to the unwanted development of natural or agricultural land. The simplest solution is to regulate that no recreation take place at the amenity. Of course, the nice views and cleaner air may still draw development outward, and the enforcement of no recreation is necessary. Rather than prohibit recreation, raising user fees at recreation sites is a way to generate revenue for the city while simultaneously restraining sprawl. If the cost of travel to a recreation site is high, development is more likely near the site since households want the benefit of a trip without the high cost of travel to the site. If roads to the recreation site are improved to reduce the cost of travel, households will prefer to locate close to the central business district rather than the recreation site to reduce the cost of their daily commutes.Public Economics,

Identifying Individual Discount Rates and Valuing Public Open Space with Stated Preference Models

An individual's rate of time preference is an important consideration for individuals deciding whether to support a public good since the benefits of a public good often come in the future. Our study finds individual discount rates from a contingent valuation method (CVM) question where the time frame of the payment schedule is varied across surveys. We find discount rates similar to the rates found in the recent revealed preference and experimental literature of around 30%. Our CVM question addresses the preservation of additional open space adjacent to a large regional park at the urban fringe of Portland, Oregon.Resource /Energy Economics and Policy, H43, Q51, Q15,

The Role of Peer Irrigators on the Choice and Intensity of Use of Irrigation Techniques

The use and the proportion of farmland that uses prominent irrigation practices in Arkansas were evaluated. A bivariate sample selection model evaluated the determinants of the share of irrigated land in a farm that uses each practice. In addition, the relationship between the irrigation practices a peer uses and the use and intensity of five common irrigation practices was evaluated. If a peer of an Arkansas farmer used center pivot irrigation, this increased the probability that the farmer used center pivot irrigation by 66 percentage points. A peer that used pivot irrigation decreased the proportion of irrigated land that used flowmeter by 0.05. However, a peer using computerized hole selection increased the proportion of irrigated land on a farm using irrigation scheduling by 2.20. The peer effect variables were modeled with interactions for location and farm practices of a farm to examine heterogeneity in the peer relationship. A peer using computerized hole selection increased the likelihood a farmer used computerized hole selection by 55 percentage points, but if the farmer is in the south Arkansas Delta, the likelihood of using the practice increased an additional 60 percentage points. The irrigation practices in use by Arkansas farmers’ families and friends affect the decision to use and the proportion of irrigated land that uses center pivot, scientific scheduling, and computerized hole selection

Differential expression of a new isoform of DLG2 in renal oncocytoma

BACKGROUND: Renal oncocytoma, a benign tumour of the kidney, may pose a differential diagnostic problem due to overlapping phenotype with chromophobe renal cell carcinoma or other types of renal cell tumours. Therefore, identification of molecular markers would be of great value for molecular diagnostics of this tumour type. METHODS: In the current study we applied various techniques, including Affymetrix microarray hybridization and semiquantitative RT-PCR, to identify genes expressed differentially in renal oncocytomas. Subsequently, we used RACE and Northern blot hybridization to characterize the potential candidates for molecular diagnosis. RESULTS: We have identified new isoform of DLG2 gene, which contains 3'-end exons of the known DLG2 gene along with the hypothetical gene FLJ37266. The new isoform is specifically upregulated in renal oncocytoma, whereas the known DLG2 gene is downregulated in this type of kidney tumour. CONCLUSION: The new isoform of DLG2 is the promising candidate gene for molecular differential diagnostics of renal oncocytoma

Economic Impacts of Non-Native Forest Insects in the Continental United States

Reliable estimates of the impacts and costs of biological invasions are critical to developing credible management, trade and regulatory policies. Worldwide, forests and urban trees provide important ecosystem services as well as economic and social benefits, but are threatened by non-native insects. More than 450 non-native forest insects are established in the United States but estimates of broad-scale economic impacts associated with these species are largely unavailable. We developed a novel modeling approach that maximizes the use of available data, accounts for multiple sources of uncertainty, and provides cost estimates for three major feeding guilds of non-native forest insects. For each guild, we calculated the economic damages for five cost categories and we estimated the probability of future introductions of damaging pests. We found that costs are largely borne by homeowners and municipal governments. Wood- and phloem-boring insects are anticipated to cause the largest economic impacts by annually inducing nearly $1.7 billion in local government expenditures and approximately$830 million in lost residential property values. Given observations of new species, there is a 32% chance that another highly destructive borer species will invade the U.S. in the next 10 years. Our damage estimates provide a crucial but previously missing component of cost-benefit analyses to evaluate policies and management options intended to reduce species introductions. The modeling approach we developed is highly flexible and could be similarly employed to estimate damages in other countries or natural resource sectors

Evaluating the Return in Ecosystem Services from Investment in Public Land Acquisitions

We evaluate the return on investment (ROI) from public land conservation in the state of Minnesota, USA. We use a spatially-explicit modeling tool, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), to estimate how changes in land use and land cover (LULC), including public land acquisitions for conservation, influence the joint provision and value of multiple ecosystem services. We calculate the ROI of a public conservation acquisition as the ratio of the present value of ecosystem services generated by the conservation to the cost of the conservation. For the land scenarios analyzed, carbon sequestration services generated the greatest benefits followed by water quality improvements and recreation opportunities. We found ROI values ranged from 0.21 to 5.28 depending on assumptions about future land use change, service values, and discount rate. Our study suggests conservation is a good investment as long as investments are targeted to areas with low land costs and high service values