Transmission of employment shocks before and after the Oklahoma City tornado

This study examined the economic impact of the May 3, 1999 Oklahoma tornado outbreak on the labor markets of Oklahoma City (OK), Wichita (KS), and Kansas City (MO). In particular, this article examines the transmission of shocks to employment growth across these different labor markets. Using monthly employment data from January 1990 to December 2004, we provide empirical evidence on the cross-market relationships that existed before and after the Oklahoma City tornado. The results suggest that the impact of the wind event may have altered labor market dynamics in Oklahoma City, as well as Wichita and Kansas City.     

Steel consumption and economic activity in the UK: The integration and cointegration debate

This research examines whether a long-run stationary equilibrium relationship holds between economic activity and the consumption of crude steel within the UK. Using the theory of fractionally integrated and cointegrated processes, and allowing for the possibility that the equilibrium path changes abruptly at occasional points in time, it is possible to determine if steel consumption and economic activity follow a common stochastic trend or whether the two series randomly drift apart over time. Evidence is found to support such a long term relationship. This result is at odds with the conclusions drawn by previous researchers in the area. The reason for this difference may be due to these researchers concentrating only on I(0) and I(1) specifications, without consideration of fractional possibilities and also to a failure to account for structural breaks in the equilibrium relationship. Such conclusions are made within the framework of the ARFIMA methodology that yields reliable inferences on the degree of fractional integration and cointegration. Critical values for fractional contegration with an ARFIMA model in the presence of structural breaks are also derived in this paper.     

Relative proportions of polycyclic aromatic hydrocarbons differ between accumulation bioassays and chemical methods to predict bioavailability

Chemical methods to predict the bioavailable fraction of organic contaminants are usually validated in the literature by comparison with established bioassays. A soil spiked with polycyclic aromatic hydrocarbons (PAHs) was aged over six months and subjected to butanol, cyclodextrin and tenax extractions as well as an exhaustive extraction to determine total PAH concentrations at several time points. Earthworm (Eisenia fetida) and rye grass root (Lolium multiflorum) accumulation bioassays were conducted in parallel. Butanol extractions gave the best relationship with earthworm accumulation (r² ≤ 0.54, p ≤ 0.01); cyclodextrin, butanol and acetone-hexane extractions all gave good predictions of accumulation in rye grass roots (r² ≤ 0.86, p ≤ 0.01). However, the profile of the PAHs extracted by the different chemical methods was significantly different (p < 0.01) to that accumulated in the organisms. Biota accumulated a higher proportion of the heavier 4-ringed PAHs. It is concluded that bioaccumulation is a complex process that cannot be predicted by measuring the bioavailable fraction alone.     

Near‐Surface Disposal Performance Assessment: Modeling Monthly Precipitation and Temperature in Various Climate Environments

A more stable and extensive analysis of climate is necessary to simulate long‐term impacts associated with climate change. The exponential dispersion model (EDM) family of distributions, a popular choice when characterizing precipitation levels and temperature in different climate environments, is being considered for its applicability to near‐surface disposal performance assessments. In this study, the EDM family is examined to determine if there is a preferred distributional form within the family for these parameters using data from two sites whose climate environments are quite different. One site is in a semiarid environment and the other is in a humid environment. In addition, the merits of selecting a different distributional form to represent each calendar month of precipitation and temperature data are explored. Results show that the gamma distribution was most often determined to be the best fit to recorded precipitation data. When considering temperature, however, the Weibull distribution proved to be a better fit. These results suggest that greater precision may be possible when temperature and precipitation serve as inputs to modeling activities, if these parameters are allowed to be represented by different distributions and derived by calendar month. Ultimately, the approach provides a more far‐reaching examination of historical records and provides an increase in confidence, when used in the evaluation of long‐term climate impacts associated with near‐surface disposal facilities. © 2013 Wiley Periodicals, Inc.     

The Perceived Implications of an Outsourcing Model on Governance within British Columbia Provincial Parks in Canada: A Quantitative Study

Good governance is of paramount importance to the success of parks and protected areas. This research utilized a questionnaire for 10 principles of governance to evaluate the outsourcing model used by British Columbia Provincial Parks, where profit-making corporations provide all front country visitor services. A total of 246 respondents representing five stakeholder groups evaluated the model according to each principle, using an online survey. Principal component analysis resulted in two of the 10 principles (equity and effectiveness) each being split into two categories, leading to 12 governance principles. Five of the 12 criteria received scores towards good governance: effectiveness outcome; equity general; strategic vision; responsiveness; and effectiveness process. One criterion, public participation, was on the neutral point. Six criteria received scores below neutral, more towards weak governance: transparency; rule of law; accountability; efficiency; consensus orientation; and, equity finance. The five stakeholder groups differed significantly on 10 of the 12 principles (P < .05). The 2 exceptions were for efficiency and effectiveness process. Seven of the 12 criteria followed a pattern wherein government employees and contractors reported positive scores, visitors and representatives of NGOs reported more negative scores, and nearby residents reported mid-range scores. Three criteria had government employees and contractors reporting the most positive scores, residents and visitors the most negative scores, and NGO respondents reporting mid-range scores. This research found evidence that perceptions of governance related to this outsourcing model differed significantly amongst various constituent groups.     

Collective guilt mediates the effect of beliefs about global warming on willingness to engage in mitigation behavior

The present research examines whether collective guilt for an ingroup's collective greenhouse gas emissions mediates the effects of beliefs about the causes and effects of global warming on willingness to engage in mitigation behavior. In Study 1, we manipulate the causes and effects of global warming and then measure collective guilt. Results demonstrate that collective guilt for Americans' greenhouse gas emissions is stronger when participants believe that global warming is caused by humans and will have minor effects. Study 2 employs the same manipulations and then measures collective guilt and collective anxiety, as well as willingness to conserve energy and pay green taxes. This study replicates the effect from Study 1 and rules out collective anxiety as a plausible alternative mediator. Collective guilt for Americans' greenhouse emissions was the only reliable mediator of the effect of beliefs about global warming on willingness to engage in mitigation behaviors. The importance of collective guilt as a tool for promoting global warming mitigation is discussed.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

LANDSCAPE ATTRIBUTES AS CONTROLS ON GROITHD WATER NITRATE REMOVAL CAPACITY OF RIPARIAN ZONES1

ABSTRACT: Inherent site factors can generate substantial variation in the ground water nitrate removal capacity of riparian zones. This paper examines research in the glaciated Northeast to relate variability in ground water nitrate removal to site attributes depicted in readily available spatial databases, such as SSUIRGO. Linking site‐specific studies of riparian ground water nitrate removal to spatial data can help target high‐value riparian locations for restoration or protection and improve the modeling of watershed nitrogen flux. Site attributes, such as hydric soil status (soil wetness) and geomorphology, affect the interaction of nitrate‐enriched ground water with portions of the soil ecosystem possessing elevated biogeochemical transformation rates (i.e., biologically active zones). At our riparian sites, high ground water nitrate‐N removal rates were restricted to hydric soils. Geomorphology provided insights into ground water flowpaths. Riparian sites located on outwash and organic/alluvial deposits have high potential for nitrate‐enriched ground water to interact with biologically active zones. In till deposits, ground water nitrate removal capacity may be limited by the high occurrence of surface seeps that markedly reduce the time available for biological transformations to occur within the riparian zone. To fully realize the value of riparian zones for nitrate retention, landscape controls of riparian nitrate removal in different climatic and physiographic regions must be determined and translated into available spatial databases.     

A land use database and examples of biogenic isoprene emission estimates for the state of Texas, USA

Using data from a variety of sources, land use and vegetation in Texas were mapped with a spatial resolution of approximately 1 km. Over 600 classifications were used to characterize the land use and land cover throughout the state and field surveys were performed to assign leaf biomass densities, by species, to the land cover classifications. The total leaf biomass densities associated with these land use classifications ranged from 0 to 556 g/m², with the highest assigned total and oak leaf biomass densities located in central and eastern Texas. The land cover data were used as input to a biogenic emissions model, GLOBEIS2. Estimates of biogenic emissions of isoprene based on GLOBEIS2 and the new land cover data showed significant differences when compared to biogenic isoprene emissions estimated using previous land cover data and emission estimation procedures. For example, for one typical domain in eastern Texas, total daily isoprene emissions increased by 38% with the new modeling tools. These results may ultimately affect the way in which ozone and other photochemical pollutants are modeled and evaluated in the state of Texas.     

Vapor intrusion risk evaluation using automated continuous chemical and physical parameter monitoring

Vapor intrusion risk characterization efforts are challenging due to complexities associated with background indoor air constituents, preferential subsurface migration pathways, and representativeness limitations associated with traditional randomly timed time‐integrated sampling methods that do not sufficiently account for factors controlling concentration dynamics. The U.S. Environmental Protection Agency recommends basing risk related decisions on the reasonable maximum exposure (RME). However, with very few exceptions, practitioners have not been applying this criterion. The RME will most likely occur during upward advective flux conditions. As such, for RME determinations, it is important to sample when upward advective flux conditions are occurring. The most common vapor intrusion assessment efforts include randomly timed sample collection events, and therefore do not accurately yield RME estimates. More specifically, researchers have demonstrated that randomly timed sampling schemes can result in false negative determinations of potential risk corresponding to RMEs. For sites experiencing trichloroethylene (TCE) vapor intrusion, the potential for acute risks poses additional challenges, as there is a critical need for rapid response to exposure exceedances to minimize health risks and liabilities. To address these challenges, continuous monitoring platforms have been deployed to monitor indoor concentrations of key volatile constituents, atmospheric pressure, and pressure differential conditions that can result in upward toxic vapor transport and entry into overlying buildings. This article demonstrates how vapor intrusion RME‐based risks can be successfully and efficiently determined using continuous monitoring of concentration and parameters indicating upward advective chemical flux. Time series analyses from multiple selected 8‐ and 24‐hr time increments during upward advective TCE flux conditions were performed to simulate results expected from the most commonly employed sampling methods. These analyses indicate that, although most of the selected time increments overlap within the same 24‐hr window, results and conclusions vary. As such, these findings demonstrate that continuous monitoring of concentration and parameters such as differential pressure and determination of a time‐weighted concentration average over a selected duration when upward advective flux is occurring can allow for a realistic RME‐based risk estimate.