UMD Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/3
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.
More information is available at Theses and Dissertations at University of Maryland Libraries.
Browse
6 results
Search Results
Item Essays on Firm Financing, Investment, and Growth(2019) Penciakova, Veronika; Kalemli-Ozcan, Sebnem; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation studies the relationship between firm financing, investment, and growth. Chapter 1 makes use of a unique dataset that combines ownership data, Census Bureau data, and patenting data to study whether firms held by owners with more diversified business interests engage in more growth-enhancing risky innovation. I document that higher owner diversification leads to riskier innovation, after taking into account firm life cycle characteristics, access to finance, other features of ownership structure, and inherent firm and owner characteristics. I also provide evidence that diversification matters at the sector level, with sectors characterized by higher diversification exhibiting higher risky innovation, revenue, volatility, and growth. I present a stylized model that rationalizes these empirical findings. Chapter 2 studies the financial leverage of U.S. firms over their life-cycle and the implications of leverage for firm growth and response to shocks using a new dataset that combines private firms' balance sheets with Census Bureau data. We show that firm age and size are good predictors of leverage for private firms but not for publicly-listed ones. Using the Great Recession as a shock to financial conditions, we show that during the Great Recession leverage declines for private, but not public firms. We also provide evidence that private firms' growth is positively associated with leverage, while public firms' growth is not. Chapter 3 explores the extent to which interest rate fluctuations during sudden stops contribute to resource misallocation and explain the sharp decline in productivity observed during these episodes. Using firm-level data from Chile, I show evidence of rising misallocation during the 1998 sudden stop and evidence of hiring and investment frictions that could trigger this rising dispersion and subsequent decline in productivity. I then study the contribution of interest rate level and volatility shocks to this rise in misallocation using a small open economy model featuring heterogeneous firms that are subject to non-convex capital and labor adjustment frictions and calibrated using firm-level data from Chile. The model is qualitatively consistent with the rise in dispersion of marginal products and the decline in productivity observed during the sudden stop crisis.Item THE ORGANISMAL AND POPULATION EFFECTS OF CLIMATE CHANGE ON JUVENILE BLUE CRAB (CALLINECTES SAPIDUS) IN THE PATUXENT RIVER, CHESAPEAKE BAY(2017) Glandon, Hillary Lane; Miller, Thomas J; Paynter, Kennedy T; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Future climate scenarios predict an increase in temperature and dissolved carbon dioxide (pCO2) of the marine environment in the next century. Calcifying marine invertebrates are thought to be especially vulnerable to increases in pCO2 and although the effect of increasing temperature in many of these taxa is understood, less is known about the interactive effects of these stressors on the physiology of calcifying invertebrates. In the present study, juvenile blue crab (Callinectes sapidus) were exposed predicted future levels of temperature and pCO2 in a 2x2 factorial design for two complete molts (approximately 30 days). Increased temperature caused a significant increase in crab growth rate and food consumption, but at a cost to carapace thickness and chemistry. The carapaces of individuals exposed to increased temperature were significantly thinner and had significantly lower percent high-magnesium calcite (HMC), the mineral from which the carapace derives its strength. Although there was a significant increase in percent HMC in response to increased pCO2, this was paired with an increase in the concentration of magnesium, complicating the overall effect of increased pCO2 on the carapace. The temperature range tested in this study was not large enough to elicit a significant difference in mean oxygen consumption rate. Crabs were resilient to exposure to extremely high levels of pCO2; there was no significant effect of increased pCO2 on crab growth rate, food consumption, or oxygen consumption rate. Individual physiological response data were utilized in concert with historical and predicted water temperatures to determine effects of future predicted increases in water temperature on blue crab overwintering behavior in the Chesapeake Bay. Model data indicated a significant shortening of the overwintering period from approximately 3.5 months currently to between 1.5 and 3 months, depending on the climate model utilized for the predictions. Increases to growing season length, combined with predicted increases in crab growth rate and food consumption, indicate that in the future blue crab will mature faster and may possibly grow year-round, similar to individuals that live in the southern extent of the species’ range.Item Development and Application of Predictive Models for Survival, Growth, and Death of Enteric Pathogens in Leafy Greens Supply Chain(2016) Mishra, Abhinav; Pradhan, Abani K.; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Leafy greens are essential part of a healthy diet. Because of their health benefits, production and consumption of leafy greens has increased considerably in the U.S. in the last few decades. However, leafy greens are also associated with a large number of foodborne disease outbreaks in the last few years. The overall goal of this dissertation was to use the current knowledge of predictive models and available data to understand the growth, survival, and death of enteric pathogens in leafy greens at pre- and post-harvest levels. Temperature plays a major role in the growth and death of bacteria in foods. A growth-death model was developed for Salmonella and Listeria monocytogenes in leafy greens for varying temperature conditions typically encountered during supply chain. The developed growth-death models were validated using experimental dynamic time-temperature profiles available in the literature. Furthermore, these growth-death models for Salmonella and Listeria monocytogenes and a similar model for E. coli O157:H7 were used to predict the growth of these pathogens in leafy greens during transportation without temperature control. Refrigeration of leafy greens meets the purposes of increasing their shelf-life and mitigating the bacterial growth, but at the same time, storage of foods at lower temperature increases the storage cost. Nonlinear programming was used to optimize the storage temperature of leafy greens during supply chain while minimizing the storage cost and maintaining the desired levels of sensory quality and microbial safety. Most of the outbreaks associated with consumption of leafy greens contaminated with E. coli O157:H7 have occurred during July-November in the U.S. A dynamic system model consisting of subsystems and inputs (soil, irrigation, cattle, wildlife, and rainfall) simulating a farm in a major leafy greens producing area in California was developed. The model was simulated incorporating the events of planting, irrigation, harvesting, ground preparation for the new crop, contamination of soil and plants, and survival of E. coli O157:H7. The predictions of this system model are in agreement with the seasonality of outbreaks. This dissertation utilized the growth, survival, and death models of enteric pathogens in leafy greens during production and supply chain.Item MANAGEMENT AND CONSERVATION OF BROOK TROUT IN WESTERN MARYLAND(2015) Kazyak, David C.; Hilderbrand, Robert H; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Widespread declines have been observed in the abundance, distribution, and size structure of Brook Trout for nearly 200 years. Although broadly distributed, Brook Trout are very sensitive to environmental disturbances, and populations continue to disappear. Environmental change further threatens the persistence of wild Brook Trout, and even currently secure populations may be at risk. Life history variation and population substructures further confound management, and their potential influences on population dynamics warrant further investigation. The objectives of my dissertation were to characterize Brook Trout populations in western Maryland and use this information to forecast alternative futures. We used a large-scale mark-recapture survey (>3,000 marked fish), molecular tools, and simulation modeling to gain a comprehensive understanding of the structure and function of Brook Trout populations in western Maryland. We found that rapid visual assessment was a valid technique (92% accuracy after training) for determining sex in Brook Trout. We found significant variability in individual growth rates (0-144 mm*y-1), with marked influences of year, sex, size, and stream. We also detected the presence of cryptic metapopulations occurring on a small spatial scale and in the absence of physical barriers to movement. Population substructures such as sex or lineage are easily overlooked, yet they may have measurable and potentially important differences in vital rates. Simulation modeling under current and alternative conditions suggested that environmental stochasticity exerts a strong influence on the population dynamics of wild Brook Trout in western Maryland. Population dynamics were driven by pulse-driven recruitment that was weakly related to spawner abundance. Changes in adult survival, representative of a range of management scenarios, had a considerable impact on population resilience. Conversely, changes in the growth rates of Brook Trout resulted in small changes to population resilience. Enhanced adult survival resulted in a greater abundance of large fish. Collectively, these results suggest regulatory approaches may offer some utility in promoting population resilience while enhancing the quality of the fishery, but are likely insufficient to fully offset the impacts of predicted environmental changes.Item Essays on International Finance(2012) Im, Fernando Gabriel; Vegh, Carlos; Reinhart, Carmen; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In the first paper, I use industry-level data to investigate the impact of exchange rate arrangements on the productive structure of the economy. The identification strategy has similarities with the methodology followed in the literature on heterogeneous effects of financial development. A de facto exchange rate regime classification is used to sort pegs and floats. My findings suggest that industries that have higher working capital needs grow faster under exchange rate stability. A fixed exchange rate regime could lower currency or country risk, leading to greater availability of funds and a reduction in the cost of financing. Since loans are often denominated in foreign currency or indexed to the exchange rate in developing countries, firms with higher working capital needs would prefer exchange rate stability, which may lower interest rates in foreign currency and provide easier access to credit. The second paper investigates the behavior of output across large devaluations and depreciations. First, I define a currency crisis as an episode in which the nominal exchange rate increases by 15%. Then I proceed to classify them into devaluations and depreciations using Reinhart and Rogoff (2004) exchange rate classification. Once these episodes are sorted out, I analyze the behavior of output across them. As in previous studies, I find that the majority of the currency crisis episodes have been contractionary for 1970-2007. When I separate currency crisis episodes between devaluations and depreciations, I find that the former have been associated with larger output losses for middle income economies. These findings are consistent with the fact that middle income countries are often subject to currency mismatches. As a result, they may opt for an exchange rate regime that exhibits relatively more stability. This is well documented in Calvo and Reinhart (2002), a behavior they termed "fear of floating". However, in the case of a currency crisis, the negative impact on output growth is likely to be larger for countries that have adopted a fixed exchange rate regime. This result is also supported by the larger magnitude of the estimated output losses when we use a higher threshold to define currency crisis episodes.Item Essays in Trade and Development(2004-08-09) Roy, Devesh; Panagariya, Arvind; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation involves two set of papers. The first chapter contains a brief introduction of the issues covered in this thesis. In the first set of papers (chapters 2 and 3) I investigate the use of product standards in international trade. Product standards relate to restrictions on the attributes of a product that must be satisfied before the product becomes eligible to be sold in a particular market. The World Trade Organization ruling on product standards requires member countries to apply equal standards on the home produced good and the imported good. This is called the national treatment rule. In the first part of the dissertation (Chapters 2 and 3) I analyze the role of national treatment rule in the case of product standards. Chapter 4 evaluates the growth experience of Mauritius in the light of the explanations put forward in the empirical growth literature. As an African country Mauritius stands out as an exception, not only having a much higher growth rate than an average African country but also maintaining growth as a sustained phenomenon. I demonstrate that this exceptional growth performance of Mauritius has occurred because of some unique institutional features of Mauritius, making it different from the rest of Africa.