938 resultados para [JEL:Q1] Agricultural and Natural Resource Economics
Resumo:
In this dissertation I quantify residential behavior response to interventions designed to reduce electricity demand at different periods of the day. In the first chapter, I examine the effect of information provision coupled with bimonthly billing, monthly billing, and in-home displays, as well as a time-of-use (TOU) pricing scheme to measure consumption over each month of the Irish Consumer Behavior Trial. I find that time-of-use pricing with real time usage information reduces electricity usage up to 8.7 percent during peak times at the start of the trial but the effect decays over the first three months and after three months the in-home display group is indistinguishable from the monthly treatment group. Monthly and bi-monthly billing treatments are not found to be statistically different from another. These findings suggest that increasing billing reports to the monthly level may be more cost effective for electricity generators who wish to decrease expenses and consumption, rather than providing in-home displays. In the following chapter, I examine the response of residential households after exposure to time of use tariffs at different hours of the day. I find that these treatments reduce electricity consumption during peak hours by almost four percent, significantly lowering demand. Within the model, I find evidence of overall conservation in electricity used. In addition, weekday peak reductions appear to carry over to the weekend when peak pricing is not present, suggesting changes in consumer habit. The final chapter of my dissertation imposes a system wide time of use plan to analyze the potential reduction in carbon emissions from load shifting based on the Ireland and Northern Single Electricity Market. I find that CO2 emissions savings are highest during the winter months when load demand is highest and dirtier power plants are scheduled to meet peak demand. TOU pricing allows for shifting in usage from peak usage to off peak usage and this shift in load can be met with cleaner and cheaper generated electricity from imports, high efficiency gas units, and hydro units.
Resumo:
As climate change continues to impact socio-ecological systems, tools that assist conservation managers to understand vulnerability and target adaptations are essential. Quantitative assessments of vulnerability are rare because available frameworks are complex and lack guidance for dealing with data limitations and integrating across scales and disciplines. This paper describes a semi-quantitative method for assessing vulnerability to climate change that integrates socio-ecological factors to address management objectives and support decision-making. The method applies a framework first adopted by the Intergovernmental Panel on Climate Change and uses a structured 10-step process. The scores for each framework element are normalized and multiplied to produce a vulnerability score and then the assessed components are ranked from high to low vulnerability. Sensitivity analyses determine which indicators most influence the analysis and the resultant decision-making process so data quality for these indicators can be reviewed to increase robustness. Prioritisation of components for conservation considers other economic, social and cultural values with vulnerability rankings to target actions that reduce vulnerability to climate change by decreasing exposure or sensitivity and/or increasing adaptive capacity. This framework provides practical decision-support and has been applied to marine ecosystems and fisheries, with two case applications provided as examples: (1) food security in Pacific Island nations under climate-driven fish declines, and (2) fisheries in the Gulf of Carpentaria, northern Australia. The step-wise process outlined here is broadly applicable and can be undertaken with minimal resources using existing data, thereby having great potential to inform adaptive natural resource management in diverse locations.
Resumo:
Petrophysical investigations are fundamental to natural resource exploration. In order to recognise the geothermal potential of sedimentary rocks in central Poland, 259 samples were collected from prospective deep-lying geothermal reservoirs. Parameters measured include bulk density, skeletal density, effective porosity, permeability, average pore diameter and specific surface. Results indicate that at great depths (mostly > 3,000 m below surface) sedimentary rocks show low values of porosity (mainly less than 5%) and permeability (only sporadically in excess of 1 md). These values call for a petrothermal use of reservoirs, for which an Enhanced Geothermal System (EGS) was developed. Reser- voirs suited for the EGS are Carboniferous and Lower Triassic sandstones in the central part of Poland (Mogilno-Łódź Trough region and a small part of the Kujawy Swell and Fore-Sudetic regions). In addition, Carboniferous limestones in this area are potentially prospective.
Resumo:
This dissertation focuses on the greenhouse and nursery industry in the United States. Two major issues are explored: irrigation and plant disease. The first two essays examine wireless soil-moisture sensor networks, an emerging technology that measures soil moisture and optimizes irrigation levels in real time. The first essay describes a study in which a nationwide survey of commercial growers was administered to generate estimates of grower demand and willingness to pay for sensor networks. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. In the second essay, yields, time-to-harvest, and plant quality were analyzed to measure sensor network profitability. Sensor-based irrigation was found to increase revenue by 62% and profit by 65% per year. The third essay investigates greenhouse nursery growers’ response to a quarantine imposed on the west coast of the United States from 2002 to present for the plant pathogen that causes Sudden Oak Death. I investigate whether growers choose to 1) improve their sanitation practices, which reduces the underlying risk of disease without increasing the difficulty of detecting the pathogen, 2) increase fungicide use, which also prevents disease but makes existing infections much harder to detect, or 3) change their crop composition towards more resistant species. First, a theoretical model is derived to formalize hypotheses on grower responses to the quarantine, and then these predictions are empirically tested using several public data sources. I do not find evidence that growers improve their sanitation practices in response to the quarantine. I do, however, find evidence that growers heavily increase their fungicide use in response to a quarantine policy that requires visual (as opposed to laboratory) inspection for the disease before every crop shipment, suggesting that the quarantine may have the adverse effect of making the pathogen harder to identify. I also do find evidence that growers shift away from susceptible crops and towards resistant crops.
Resumo:
Nonpoint sources (NPS) pollution from agriculture is the leading source of water quality impairment in U.S. rivers and streams, and a major contributor to lakes, wetlands, estuaries and coastal waters (U.S. EPA 2016). Using data from a survey of farmers in Maryland, this dissertation examines the effects of a cost sharing policy designed to encourage adoption of conservation practices that reduce NPS pollution in the Chesapeake Bay watershed. This watershed is the site of the largest Total Maximum Daily Load (TMDL) implemented to date, making it an important setting in the U.S. for water quality policy. I study two main questions related to the reduction of NPS pollution from agriculture. First, I examine the issue of additionality of cost sharing payments by estimating the direct effect of cover crop cost sharing on the acres of cover crops, and the indirect effect of cover crop cost sharing on the acres of two other practices: conservation tillage and contour/strip cropping. A two-stage simultaneous equation approach is used to correct for voluntary self-selection into cost sharing programs and account for substitution effects among conservation practices. Quasi-random Halton sequences are employed to solve the system of equations for conservation practice acreage and to minimize the computational burden involved. By considering patterns of agronomic complementarity or substitution among conservation practices (Blum et al., 1997; USDA SARE, 2012), this analysis estimates water quality impacts of the crowding-in or crowding-out of private investment in conservation due to public incentive payments. Second, I connect the econometric behavioral results with model parameters from the EPA’s Chesapeake Bay Program to conduct a policy simulation on water quality effects. I expand the econometric model to also consider the potential loss of vegetative cover due to cropland incentive payments, or slippage (Lichtenberg and Smith-Ramirez, 2011). Econometric results are linked with the Chesapeake Bay Program watershed model to estimate the change in abatement levels and costs for nitrogen, phosphorus and sediment under various behavioral scenarios. Finally, I use inverse sampling weights to derive statewide abatement quantities and costs for each of these pollutants, comparing these with TMDL targets for agriculture in Maryland.
Resumo:
This dissertation is composed of three essays covering two areas of interest. The first topic is personal transportation demand with a focus on price and fuel efficiency elasticities of mileage demand, challenging assumptions common in the rebound effect literature. The second topic is consumer finance with a focus on small loans. The first chapter creates separate variables for fuel prices during periods of increasing and decreasing prices as well as an observed fuel economy measure to empirically test the equivalence of these elasticities. Using a panel from Germany from 1997 to 2009 I find a fuel economy elasticity of mileage of 53.3%, which is significantly different from the gas price elasticity of mileage during periods of decreasing gas prices, 4.8%. I reject the null hypothesis or price symmetry, with the elasticity of mileage during period of increasing gas prices ranging from 26.2% and 28.9%. The second chapter explores the potential for the rebound effect to vary with income. Panel data from U.S. households from 1997 to 2003 is used to estimate the rebound effect in a median regression. The estimated rebound effect independent of income ranges from 17.8% to 23.6%. An interaction of income and fuel economy is negative and significant, indicating that the rebound effect may be much higher for low income individuals and decreases with income; the rebound effect for low income households ranged from 80.3% to 105.0%, indicating that such households may increase gasoline consumption given an improvement in fuel economy. The final chapter documents the costs of credit instruments found in major mail order catalogs throughout the 20th century. This study constructs a new dataset and finds that the cost of credit increased and became stickier as mail order retailers switched from an installment-style closed-end loan to a revolving-style credit card. This study argues that revolving credit's ability to decrease salience of credit costs in the price of goods is the best explanation for rate stickiness in the mail order industry as well as for the preference of revolving credit among retailers.
Resumo:
The 2014 Farm Bill created Supplemental Coverage Option (SCO), a new add-on crop insurance option which provides supplemental coverage on a producer’s underlying crop insurance policy. SCO operates by mimicking a producer’s individual crop insurance coverage and covering a portion of the deductible based on county-level yield or revenue. SCO is available in select Maryland counties for apples, barley, corn, grain sorghum, green peas, oats, peaches, processing beans, soybeans, sweet corn, and winter wheat, as of the 2017 crop year. USDA’s Risk Management Agency (RMA) continues to expand covered counties and crops covered, and begin distinguishing by practices (such as irrigated compared to non-irrigated).
Resumo:
The genus Trichogramma Westwood (Hymenoptera: Trichogrammatidae) includes insect egg parasitoids that are widely used throughout the world as control agents of pest insects. The aim of this study was to identify the species of Trichogramma naturally associated with the eggs of lepidopteran pests of the following agricultural and horticultural crops: collards, Brassica oleracea L. (Brassicales: Brassicaceae); papaya, Carica papaya L. (Capparales: Caricaceae); tomato, Lycopersicon esculentum Mill. (Solanales: Solanaceae); cassava, Manihot esculenta Crantz (Malpighiales: Euphorbiaceae); banana, Musa sp. L. (Zingiberales: Musaceae); passion fruit, Passiflora sp. Degener (Malpighiales: Passifloraceae); sugarcane, Saccharum sp. L. (Poales: Poaceae); and corn (maize), Zea mays L. (Poales: Poaceae); and an invasive species (Sodom?s apple milkweed, Calotropis procera Aiton; Gentianales: Apocynaceae) in the semiarid region of Minas Gerais, Brazil. We report natural parasitism by Trichogramma in eggs of Agraulis vanillae vanillae (L.) (Lepidoptera: Nymphalidae), Antichloris eriphia F. (Lepidoptera: Arctiidae), Danaus sp. (L.) (Lepidoptera: Nymphalidae), Diatraea saccharalis F. (Lepidoptera: Crambidae), Erinnyis ello L. (Lepidopera: Sphingidae), and Protambulyx strigilis L. (Lepidopera: Sphingidae). In total, 2,242 specimens of Trichogramma were obtained, belonging to the species T. pretiosum Riley, T. manicobai Brun, Moraes & Soares, T. marandobai Brun, Moraes & Soares, and T. galloi Zucchi. These species of Trichogramma may be candidates for biological control programs of lepidopteran pests in the semiarid region of Minas Gerais and in other semiarid regions.