Browsing by Subject "Agricultural and Applied Economics"

Now showing 1 - 9 of 9
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    Designing optimal strategies for surveillance and control of invasive forest pests.
    (2011-04) Horie, Tetsuya
    This thesis focuses on the theme of detecting and managing invasive forest pests. First, we model optimal detection of sub-populations of invasive species that establish ahead of an advancing front. We find that the uninfested landscape is divided into two zones, characterized by different dynamically optimal management plans: a suppression zone and an eradication zone. In the suppression zone, optimal detection effort increases with distance from the front. At the distance where the suppression zone yields to the eradication zone, optimal detection effort plateaus at its maximum level. Second, we develop a model of optimal surveillance and control of forest pathogens and apply it to the case of oak wilt in a region within Anoka County, Minnesota. We develop a cost curve associated with the expected fraction of healthy trees saved from becoming infected. We also explore characteristics of sites selected for surveillance. In particular, we examine the characteristics of sites that make them high-priority sites for surveillance when the budget level is relatively low. We find that the best surveillance strategy is to prioritize sites with relatively low expected unit surveillance cost per tree saved from infection. Our results offer practical guidance to managers in charge of deciding how and where to spend limited public dollars when the goal is to reduce the number of trees newly infected by oak wilt. Third, we model a private landowners' forest protection problem, in which each landowner decides among three possible strategies: prevention, monitoring and treatment, and no treatment. We find that the proportion of landowners taking preventive and no action increases as the accuracy of monitoring decreases; monitoring ceases to be chosen when monitoring accuracy declines below a threshold value. We also investigate the possible effects of a policy that raises the accuracy of monitoring on social welfare in both the landowners' equilibrium and the full information social optimum. We find that the policy closes the gap in social welfare between the landowners' equilibrium and the full information social optimum. However, it decreases social welfare in the full information social optimum.
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    An economic evaluation of the roots and fruits of intellectual property Rights for U.S. horticultural Plants.
    (2010-05) Drew, Jennifer
    Most prior studies have failed to empirically reveal any significant economic or innovation effects of intellectual property rights for plant products. Perhaps this is because these studies focused on the wrong crops (i.e., wheat, soybeans, and corn) or were unduly circumscribed in the types of intellectual property under consideration (i.e., U.S. plant variety protection and utility patents). This study's focus is on the economic effects of intellectual property rights for horticultural crops in the United States which have garnered the lion's share of the plant protection. Highlighting differences between the horticultural and agricultural sectors, the first part of this study analyzes the roots of intellectual property rights for plants and associated plant markets and their evolution in the United States. This analysis reveals large structural changes in the pattern of intellectual property protection for plants in the United States which reflects advances in plant related science and technologies, market changes, as well as policies and practices affecting plant-related intellectual property. These structural changes include changes in the form of protection being sought—be it plant patents, utility patents, or plant variety protection certificates; the agent (e.g., individuals, firms, universities, or government agencies) seeking protection; and the plant species being protected. Ornamental plants account for a large and growing share of the U.S. plant economy whether measured as a share of property rights issued or the real value of plant products produced. The notable increase in plant patent applications in the horticultural sector in recent years is paralleled by a rapidly growing effort to brand high–valued crops and garner value by protecting of cultivar innovations with other forms of legal protection such as trademarks. The second part of this study focuses on the fruits of intellectual property rights for ornamental plants. Ornamental plants account for much of the intellectual property rights for plants, thus providing a potentially more fertile area in which to examine the price consequences of plant-related intellectual property rights. A large, unique, purpose built data set is used to identify the sources of differences in the wholesale price of ornamental plant varieties. A hedonic pricing model was adapted to the particulars of the ornamental plant sector and the data. The hedonic decomposition of plant prices made it possible to identify varietal price premiums associated with plant patent and trademark attributes. After controlling for a host of plant attributes that affect plant prices, an average price premium of 23 percent was identified for plants protected by plant patents compared with those with no such protection. Likewise, the average value of the trademark premium was 2.5 percent, indicating that the branding value of the name trademark is much lower. Surprisingly, when these two plant intellectual properties were used together on one cultivar, premiums were nearly 7 percent lower than if neither were used, a result which raises questions for further research. The premiums for the plant patent and name trademark vary between different firms and between different species particularly between herbaceous perennial and woody species and specializing firms.
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    Economic, environmental, and endowment effects on childhood obesity and school performance.
    (2009-01) Wendt, Minh Hoang Do
    A surge in the prevalence of childhood obesity over the last several decades in the U.S. has raised concerns from not only public health authorities, but also from various fields such as medicine, sociology, psychology, and economics. The present research examines factors associated with childhood obesity in the U.S. The first part of this dissertation identifies economic, environmental, and endowment effects on childhood obesity; the second examines the relationship between childhood malnutrition, both underweight and overweight, on school performance. A national longitudinal dataset "Early Childhood Longitudinal Study, Kindergarten-Fifth Grade" (ECLS-K), containing data for 12,719 children from fall 1998 (Kindergarten year) through spring 2004 (Fifth grade), with additional information from the U.S. Census and the Bureau of Labor Statistics, is used. A mixed-effect ordered Logit (proportional odds) is used in the first part of this study, and a mixed-effects linear model is used in the second. The first part is estimated in two separate regressions, a reduced-form health demand function, and a health production function. In the first part of the study, results for the health demand function indicate that the likelihood of childhood obesity increases with the higher number of working hours per week by parent(s), lower level of parents' socioeconomic status (parents' education and household income), fewer number of siblings, higher child birth weight, and minority status. The results for the health production function, which includes a set of health inputs as explanatory variables, indicate that less-healthy parents, school lunch participation, and fewer physical activities are correlated with the higher likelihood of children being overweight. The results from the second part show that malnourished children, either underweight or overweight, achieve lower scores on standardized tests, particularly for mathematics. This pattern remains significant, whether contemporaneous weight status or changes in weight status over time are used as explanatory variables. Additionally, students with higher frequency of reading time, fewer hours spent watching TV, and fewer hours in child care (i.e., non-parental care) achieve higher test scores. A household's higher socio-economic status (parents' education and income), parents' expectations for their child's schooling, parents' higher level of involvement with school activities, and households that have a computer for their child's use are correlated with higher school achievement. On the other hand, students with more siblings, students whose family move frequently, and households with some level of food insecurity are associated with lower school performance. Student test scores increase with teacher experience, which is measured by the number of teaching years (for reading scores) and those with a masters or professional degree (for math scores). School institutional characteristics that are important for students' higher achievement are private school (for reading scores), lower teacher turn over rates, higher percentage of students in school testing at or above the national level, and a lower percentage of minority students. Taken together, the results from both parts of this study emphasize the need to reduce childhood malnutrition, particularly childhood obesity. This task can not be accomplished without a combination of government policies, parents' time commitment, and school's involvement; all are needed to address problems of childhood obesity. Schools can promote good nutrition through healthy school meals and encourage physical activities through physical and health education programs. Given the link between parental working hours and children being overweight, flexibility in working hours and benefits such as health insurance for parents who work part time could promote effective parenting. Most importantly, government programs that affect both school-based and home-based efforts such as school lunch, physical education programs, and parental working conditions play a major role in curbing the childhood obesity problem.
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    Essays on economics of information in environmental management.
    (2008-06) Konishi, Yoshifumi
    This manuscript is a collection of essays that investigate the effects of information on optimal environmental and resource policies. Two essays are paired, and each pair examines a well-defined policy problem. The first and the second essays study how a regulator should determine efficient levels of public pollution control, private abatement, and information provision efforts in an environment where environmental pollution risks are endogenous in private self-protection. The first essay proposes a welfare valuation theory amenable to analyses in this context. The second essay proposes an empirical strategy to implement the theory in practice, and demonstrates how policies may be misguided if regulators follow conventional valuation strategies. The third and the fourth essays jointly study the economic consequences of binary ecolabeling. I propose a theory of green consumerism, which correctly accounts for asymmetric information and is consistent with empirical evidence. Given the consumer theory thus established, the fourth essay finds an empirically executable way to set an optimal level of environmental standard for binary ecolabeling.
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    Essays on health, education and behavioral choices.
    (2010-04) Konishi(Zhao), Meng
    My dissertation is composed of two essays that investigate the interrelationship between consumers' health, education, behavioral choices, and perceptions. The first essay evaluates the impact of teenage smoking on schooling and estimates the lifetime income loss due to lower educational achievement and attainment caused by youth smoking. Using unusually rich data from China, the study shows that youth smoking can biologically reduce learning productivity and discourage motivation to go to school (where smoking is forbidden), resulting in lower educational outcomes and, consequently, reduced lifetime income. The second essay empirically analyzes the effect of a doctor diagnosis of hypertension (high blood pressure) on food demand and nutrient intake. The study shows that three quarters of the hypertensive population in China are unaware of their condition. Adoctor's diagnosis can lead consumers to update their perceptions about their health and, therefore, make better decisions for their food choices. The study finds that, after a diagnosis of hypertension, consumers significantly reduce their daily fat intake, especially the consumption of animal oil and pork. The effect is stronger for 2004 data, compared to the 1997 and 2000 data. This suggests that consumers have become more health conscious in recent years.
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    Impact of nutrition information on consumers' food purchases.
    (2011-08) Shiratori, Sakiko
    This study estimates the impact of nutrition information provided by popular media on consumers' food purchases in U.S. grocery stores, taking omega-3 fortified eggs as an example. Household-level scanner data are analyzed with the media index for the information about health benefits of omega-3 fatty acids, which is constructed from multiple information sources by utilizing computer-coded content analysis. In addition, the welfare change of consumers is measured by the consumer surplus and the value of information is also estimated. The results show a significant positive impact of nutritional information from popular media on consumers' food choices. Consumers are quite sensitive to the prices of regular eggs, but are not very sensitive to a change in the price of omega-3 eggs. Consumer surplus increased over time. When this welfare change is investigated further using the concept of the value of information, most of the welfare change is accounted for by the information. In this way, publishing in popular media can be an effective information communication approach to promote consumers' health.
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    International migration and remittances: assessing the impact on rural households in El Salvador.
    (2008-07) Damon, Amy Lynne
    This dissertation project examines the impact of human migration and remittances on rural household behavior in El Salvador. It specifically focuses on two questions: (1) How is household labor supply allocation affected by migration and remittances? (2) How do remittances affect agricultural production outcomes at the household level? An agricultural household model that integrates migration and remittances predicts that when households are credit constrained they allocate their family labor back to their own farm when remittances are received. Further, the agricultural model suggests that when remittances are received households will invest in the production of riskier cash crops. The data used for the empirical analysis for this project cover six years and were collected in El Salvador in 1996, 1998, 2000, and 2002. The empirical analysis uses panel data to examine how changes in both the migration status of the household and remittance levels affect different family members' labor allocations. Factors that determine both migration decisions and remittance levels are also estimated. Unlike previous studies, this study finds that it is migration not remittances that affects a family's labor allocation decisions. When a household engages in migration, this increases the hours of on-farm work for all household members (adult males, females, and children) and decreases the hours of off-farm work for adult males. Remittances have no significant affect on household labor allocations. Further, a cross-sectional analysis indicates that migrant females in the United States send more remittances than male migrants. Findings regarding household agricultural outcomes suggest that migration decreases a household's coefficient of variation for agricultural revenue. Further, migrant households dedicate a larger share of their land to their house lot and basic grains production than non-migrant households. Migrant households also decrease the amount of land dedicated to cash crops other than coffee. Migrant households are more active in land rental markets, both renting more land in and renting more land out than non-migrant households. Remittances seem to have relatively little impact on agricultural production activities as compared to migration itself.
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    Parameter non-constancy in linear regression: applications of threshold regression and structural change models
    (2010-05) Adachi, Kenji
    This dissertation provides an overview of recent developments in the identification and estimation of unknown change-points. It explores the applicability and efficacy of the new approaches to the analysis of economic relationships in agricultural marketing, agricultural production, and food markets. It demonstrates via empirical analyses how the methods can be implemented and the results interpreted. In particular, this dissertation includes three empirical essays, focusing on two families of parameter-nonconstancy models: threshold regression and structural change models. In addition, given the breadth of the topics (generic dairy promotion program, rice production efficiency, and vertical price relationship) and the countries of data collected (the United States, Bangladesh, and Japan), the three empirical essays address a broad spectrum of important issues in different commodity sectors under different economic environments.