Browsing by Author "Davis, George C."

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    Applications of Applied Econometrics in the Food and Health Economic and Agribusiness Topics
    Shi, Ruoding (Virginia Tech, 2019-11-12)
    This dissertation consists of three essays in Applied Econometrics that seek a better understanding of different aspects of risk and risk management tools. The first essay is about mortality risk in Virginia coal regions. With a focus on the mortality of non-malignant respiratory diseases (NMRD), I estimate the impact of living in a coal county and find that coal-mining county residency significantly increases the probability of dying from NMRD. This statistical association is accentuated by surface coal mining, high smoking rates, lower health insurance coverage, and a shortage of doctors. The second essay evaluates the cost of a price risk management tool called futures hedging. A variety of measures illustrate considerable changes in hedging costs over time. Quantile regression results show that substantial price volatility and high margin requirements are the main factors driving high hedging costs from 2007 to 2013. The third paper investigates a health risk management tool, a public health insurance program in China called New Cooperative Medical Scheme (NCMS). I apply contract theory to characterize local governments' selective incentives in NCMS benefit designs. Empirical analysis of China Health and Nutrition Survey data indicate challenges of financial sustainability of this scheme in poor regions. The NCMS plan tends to under-cover the services that are moderately predictable and negatively correlated with plan profits, such as outpatient treatments. Preventive services are generally over-provided, perhaps due to the incentive to attract healthy participants.
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    Are Heat and Eat Policies Affecting SNAP Household Participation?
    Nikolla, Dorina (Virginia Tech, 2016-08-31)
    In the U.S., states vary in the way they link the Supplemental Nutrition Assistance Program (SNAP) and Low-Income Home Energy Assistance Program (LIHEAP). State practices that have come to be known as "Heat and Eat" (HandE) exploit a SNAP energy expense deduction in order to increase SNAP benefits. Sixteen states have used the practice at some point, with the earliest starting in 1995 and latest in 2013. This study uses variation in the timing of adoption of HandE across states to estimate the HandE's effect on SNAP participation. SNAP-LIHEAP participation links are also examined in relation to alternative state policies that bundle application costs. Using SIPP 2008 Panel data, the study employs a household fixed effects model to examine the impact of LIHEAP participation and the three SNAP-LIHEAP bundling policies on SNAP participation propensities. The results indicate that HandE policies cause a small increase in household SNAP participation, which is likely due to the fact that HandE provides additional benefits for SNAP participants. Categorical eligibility that links applications for both programs also generates higher differential probabilities of being on SNAP. These results are consistent with previous findings in the multiple program participation literature.
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    Authoritative Mothers Exhibit More Permissive Feeding Practices Eating Away from Home with their Children
    Kasparian, Michelle Marie (Virginia Tech, 2012-06-25)
    Eating away from home has been identified as one possible contributor to childhood obesity, with links to poor diet quality and higher weight status due to dietary quality of meals at restaurants and consumers' attitudes. Parenting style has been associated with children's weight status and overall attitudes toward food, with authoritative parenting being shown to help protect against childhood obesity. The current study aimed to compare and contrast parenting and feeding practices at home and in the restaurant. Twenty-five mothers with children, ages five to eight, who ate at restaurants at least two times per week participated in facilitated, individual interviews. Interviews topics included: parenting, child input in choosing restaurants and restaurant meal selection, and food rules and practices at restaurants versus at home. Socio-demographic information, parenting style, and the mothers' heights and weights were gathered, with descriptive statistics computed. Interview data were transcribed, then thematically coded using NVivo software. All mothers scored highest on authoritative parenting styles. Participating mothers were Caucasian, well-educated, with above-average family incomes. Mothers had an average of 2.2 children and a BMI of 27.9 kg/m². Mothers described more stringent behavioral expectations and more permissive food rules at restaurants. Parents had greater influence in determining whether to eat away from home and where, whereas children had greater responsibility for meal selections at restaurants. The results suggest that practices may differ at restaurants than at home, highlighting the importance of further research, along with educational and behavioral strategies directed toward mothers when eating away from home.
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    COVID-19-Related Financial Scarcity is Associated with Greater Delay Discounting But Not Probability Discounting
    Downey, Haylee; Freitas-Lemos, Roberta; Curran, Kelsey M.; Serrano, Elena L.; Davis, George C.; Stein, Jeffrey S. (2023-01-01)
    Prior laboratory studies suggest that scarcity increases delay discounting (devaluation of delayed outcomes) and disturbs other decision-making processes. Recent evidence on the effect of COVID-19 on delay discounting is mixed. In addition, no study has examined the effect of COVID-19-related scarcity on probability discounting (devaluation of probabilistic outcomes). The present study examined cross-sectional associations between COVID-19-related scarcity, delay discounting, and probability discounting. During April 2020, 1012 participants with low income were recruited on Amazon Mechanical Turk (MTurk) and completed measures of delay and probability discounting of money and food (grocery gift card), COVID-19-related financial impacts, stress, and food security. Regression analyses indicate that compared to those with no COVID-19 related financial impacts, those with severe COVID-19 related financial impacts had greater delay discounting of money and greater delay discounting of food. In addition, greater food insecurity in the past month was associated with greater delay discounting of food but not money. COVID-19 related financial impact was not associated with probability discounting of money or probability discounting of food. Combined with laboratory experiments, the present study provides additional support for the idea that scarcity or income shock may increase delay discounting, particularly during the onset of COVID-19.
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    A Developmental Cascade Model of Maltreatment, Delay Discounting, and Health Behaviors across Adolescence and Young Adulthood
    Peviani, Kristin Marie (Virginia Tech, 2022-06-15)
    Maltreatment is a pervasive global problem known to have cascading consequences that persist long after exposure subsides (Masten and Cicchetti, 2010). Maltreatment is often co-occurring, involving exposure to multiple types. Cumulative maltreatment, or exposure to multiple types of neglect and abuse, is proposed to be of critical importance for developmental psychopathology. However, a cumulative approach to studying maltreatment provides little insight into the developmental processes whereby it exerts its effects on health. Thus, we employed both a cumulative approach and a multidimensional approach to facilitate our comprehensive understanding of maltreatment experiences related to behavioral development. Given the high prevalence of maltreatment, it is important to cultivate a greater understanding of the processes linking maltreatment and health and to identify developmental periods of vulnerability to its deleterious effects. The present study uses a longitudinal design and a multidimensional approach to examine the effects of maltreatment on delay discounting and health-promoting and health-demoting behaviors during adolescence and across the transition from adolescence to young adulthood. The study sample includes 167 adolescents (aged 13–14 at Time 1; 53% male) who participated across 5 time points over 6 years. At Time 5, adolescents provided retrospective reports of their exposure to maltreatment during adolescence across ages 13–18. Delay discounting, substance use, and body mass index (BMI) were assessed at each time point. We used a developmental cascade model with autoregressive, cross-lagged, and cross-sectional associations to examine the longitudinal multivariate change processes and indirect effects from maltreatment exposure during adolescence to delay discounting and health-promoting and health-demoting behaviors during adolescence and across the transition to young adulthood. Our results indicate that cumulative maltreatment affects health-demoting behavior via its effects on delay discounting and that maltreatment of omission but not commission drives this effect. Furthermore, the findings identify adolescents exposed to maltreatment of omission as being especially vulnerable to marijuana use via elevated delay discounting. Identifying mediating processes linking maltreatment exposure to health-promoting and health-demoting behaviors may be instrumental for preventing deleterious developmental cascades and interrupting related health problems during adolescence and across the transition from adolescence to young adulthood.
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    Distinguishing between Chronic and Transient Poverty in Mozambique
    Groover, Kimberly Darnton (Virginia Tech, 2011-06-03)
    The main purpose of the study is to identify household characteristics which can 1) distinguish between the chronic poor and transient poor and 2) be feasibly implemented as targeting criterion in poverty interventions. Data for this study was drawn from Mozambique's 2008/09 Household Budget Survey and consisted of 10,832 observations. This study fills a gap in the literature by structurally determining the impact of common shocks (drought, floods and cyclones, agricultural pests, illness, death, and theft) on 1) food expenditures at the household level and 2) poverty rates at the national level. The results of the study indicate that shocks are one of the key determinants of household food expenditures. The expected impact of shocks in aggregate increases the national poverty rate by 9%. However, the impact of specific shocks on household food expenditures varies across regions and households. Further, the variables which are strongly correlated with chronic poverty differ from the variables strongly correlated with transient poverty. These results suggest the need to both more rapidly identify and enroll households exposed to shocks in short-term social protection programs and continue to improve methods targeting the chronic poor in long-term programs.
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    The Effect of Episodic Future Thinking on a Novel Measure of Behavioral Economic Demand for Exercise
    Brown, Jeremiah M. (Virginia Tech, 2024-05-06)
    Physical inactivity is a major contributor to increased disease prevalence and reduced quality of life. Measuring behavioral economic demand for exercise may enable more effective physical activity intervention development. In study one, we developed the leisure-time-as-price exercise purchase task (LT-EPT), wherein participants (n = 175) indicate hypothetical likelihood to trade leisure time for access to exercise time. We observed weak to moderate correlations between demand indices (Q1%, α, BP1, and Pmax) generated from the LT-EPT and self-reported leisure and exercise time, demonstrating initial validation of the LT-EPT. In study two, we examine the effect of episodic future thinking (EFT; vivid, personalized prospection of future events) in adults not meeting physical activity guidelines (n = 127) on demand for exercise and delay discounting (sensitivity to delayed rewards). We observed reduced delay discounting in participants randomized to engage in EFT, but no difference between EFT and health information thinking (HIT) controls. In study three, we further examined the effect of EFT on demand for exercise in adults with type 2 diabetes and obesity participating in a 24-week randomized controlled trial (n = 71). All participants engaged in a multicomponent behavioral intervention focused on weight loss and glycemic control; additionally, participants were randomized to engage in EFT or HIT thrice daily beginning in week 3. We measured demand for exercise and delay discounting (among other outcomes) at weeks 0, 8, and 24, observing no differences between EFT or HIT groups in demand indices (Q1%, α) or delay discounting at any time point. In conclusion, early evidence suggests that the LT-EPT may be a valid method to measure behavioral economic demand for exercise; however, EFT may not be an effective intervention to increase demand for exercise.
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    Effects of Incentives and Genetics on Food Choices and Weight Phenotypes in the Neuroendocrine Gene Tubby Mutant Mice
    Davis, George C.; Jacob, Johanna; Good, Deborah J. (Bentham Open, 2012-01)
    Food intake and obesity related phenotypes are greatly affected by economic factors and yet very little is known about the interaction of economic factors, genetics, behavior, and obesity phenotypes. Recent human population research suggests that a decreasing price of high fat food relative to low fat food has contributed to the current obesity epidemic in humans. The two key elements in this argument are choice and costs. We incorporate these key elements in a closed economy mouse model to study the interactions of economics, genetics, and obesity related phenotypes, using normal mice, and mice with a mutation in the hypothalamus-expressed Tub gene, which has a phenotype of adult onset obesity. Results for both genotypes indicate that as the price of the high fat food falls, consumption of that food increases and consumption of the low fat food declines, but not enough to offset the increase in high fat food so total intake and weight increases, with no statistically-significant differences between genotypes. These results are in contrast to previous literature based on an ad lib, no choice food setting. In addition, in our closed economy model, the Tub mutant showed a numerical and statistically significant increase in body fat percentage and glucose intolerance, whereas these increases were only numerical for the normal mice. Both genotypes showed numerical but statistically insignificant increases in leptin and ghrelin levels. These results show that accounting for choice in neuroeconomic studies is important to understanding the complex regulation of intake, body weight and other related phenotypes.
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    The Effects of Program Attributes on Behavior Change for Healthy Weight for Healthy Kids Program in Virginia
    Badirwang, Keeletlhoko Faith (Virginia Tech, 2012-08-09)
    Since the federal budget for EFNEP is over $66 million, it is crucial to know the effectiveness of program attributes that may bolster its effectiveness. The aim of this study was to determine how effectiveness of Youth EFNEP programs in Virginia is affected by participant, instructional and curriculum attributes for youth enrolled in Healthy Weight for Healthy Kids (HWHK). An ordered probit model was employed to study how these attributes affect dependent variables: Whole Grain, Fruits, Colored Vegetables, MyPlate, and Breathe Hard behavioral scores. The model assessed the probability of a participant having an improved score or improved behavior. Participant Attributes Results: In general, the chosen variables for participant characteristics consistently reduced the probability of participants having an improved behavior score. Instructional Attributes Results: African Americans Program Assistants were consistently associated with negative marginal effects on positive behavioral scores with the exception of the positive Breathe Hard behavioral score. Other PA attributes were not consistently associated with any behavioral models but were heterogeneous in terms of their marginal effects on the positive behavioral scores. Curriculum Attributes results: The curriculum attributes had more positive marginal effects than negative marginal effects across all the five behavioral scores. Attributes that were consistently associated with having a positive marginal effect on behavioral scores were program duration, smart foods lesson, and lesson duration. Other HWHK lessons were not consistent in increasing or reducing the probability of an improved behavior.
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    Essays on Environmental Economics with a Focus on Non-market Valuation
    Cao, Xiang (Virginia Tech, 2019-07-09)
    This dissertation consists of two research projects in the area of Environmental Economics: water-recycling technology adoption and its cost-effectiveness in the U.S. horticulture industry (in Chapter 2), and urban tree cover's impact on residential location decision making in Milwaukee, WI (in Chapter 3). Chapter 2 evaluates the economic effects of labeling plants grown with water-recycling technology (WRT) practices in selected nursery operations in the Mid-Atlantic region of Virginia, Maryland and Pennsylvania. Partial budgeting, whole enterprise-level budgeting, sensitivity and break-even analyses are conducted to determine whether consumer premiums for plants grown with recycled water are sufficient to make WRT economically feasible combined with plant eco-labeling, and how such a labeling program would affect greenhouse/nursery production costs, gross revenues and net revenues. It is concluded that consumer premiums for plants grown with recycled water could offer nursery growers a method to improve their net returns while reducing pollution runoff and improving irrigation water usage efficiency. Chapter 3 focuses on non-market valuation of environmental (dis)amenities. Specifically, this chapter investigates the impact of urban tree cover on residential property location decision in the housing market of Milwaukee, WI. Residential sorting model embedded with "horizontal preference structure" is established to estimate the heterogeneous preferences for tree cover and other land cover attributes that vary by household socio-economic characteristics and then to identify the housing property owners' demand for these land cover attributes. The first part of this chapter mainly recovers the demand for "community trees" at the census block group level combined with 10 years property transaction data and neighborhood characteristics where the median income is aggregated to represent the household annual income. It is found that "community trees" are positively valued by the housing property owners and have a positive impact on housing price due to its positive externalities. Furthermore, income is found to be a strong exogenous demand shifter, leading to heterogeneous preference for the tree cover. The second part of Chapter 3 further investigates the impacts of both nearby trees and distant trees on residential property location decision using different spatial scales of land covers measurements. Instead of aggregating block group level median income, this study matches and merges disaggregated individual household annual incomes from the Home Mortgage Disclosure Act (HMDA) dataset to mitigate the potential aggregation bias. It is found that different spatial scales of land cover measurement result in varying willingness to pay estimates, implying that housing property owners have heterogeneous demands for nearby trees and distant trees. In other words, preferences for urban tree cover not only vary by household annual income, but also differ across spatial scales of the tree cover measurement.
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    Essays on Price and Time in Trade and Household Production
    Yang, Jinyang (Virginia Tech, 2022-07-13)
    This dissertation consists of three chapters that estimate the elasticities regarding price and time in trade and household production. Chapters 1 and 2 estimate price elasticities. Chapter 1 estimates the one-factor-one-price elasticity of substitution (OOES)—or how the percentage change in the quantity of one good responds to the percentage change in the price (of itself or another good)—in an international trade context. Chapter 2 estimates the two-factor-one-price elasticity of substitution (TOES)—or the difference of percentage changes between two quantities with respect to the percentage change in the price of one good—in the context of household food production. Chapter 3 estimates the elasticity of export quantity and value with respect to delays in the time it takes to load or unload products at US ports. Chapter 1 estimates the price elasticities in agricultural trade. Armington elasticities, the elasticity of substitution between goods from different countries, are key parameters in agricultural trade policy evaluation and welfare calculation. We estimate Armington elasticities for a selected basket of 38 agricultural commodities in 5 categories by compiling a sample of 118 countries' production and trade flows. Following and extending Feenstra et al. (2018), we estimate both the micro-elasticity of substitution between foreign sources of imports and the macro-elasticity of substitution between home and imported products at the commodity level. The median of the micro- and macro-elasticities are 6.4 and 5.0, respectively. Meat products have the lowest micro- and macro-elasticities, with the micro-elasticities ranging from 4.2 (pork) to 5.0 (poultry) and the macro-elasticities ranging from 2.9 (pork) to 4.5 (beef). Crops products have the widest range of Armington elasticities, with micro-elasticities ranging from 2.5 (pigeon peas) to 90.3 (peanuts), and macro-elasticities ranging from 1.2 (pigeon peas) to 20.1 (peanuts). In line with the literature, we find that 75 percent of the agricultural commodities have numerically smaller macro-elasticities than micro-elasticities, even though only 6 of them (pork, poultry, corn, peanuts, apples, and peppers) are statistically smaller at the 5 percent level. We explore the robustness of our estimates by slicing the sample into separate periods and importing countries. Finally, we discuss the policy implications of our estimates on predicting trade due to tariff changes and understanding welfare gains from agricultural trade. Chapter 2 estimates the goods-time elasticity of substitution (EOS), the responsiveness of the difference between money and time in household production for change of opportunity cost of time (OCT). This chapter bridges the gap between literature that directly and indirectly estimates the goods-time EOS in household production. Inspired by the studies in environmental economics, we argue the opportunity cost of time in household production not only depends on wage but life-cycle dynamics and household demographics as well. We proceed with the estimation by two strategies: direct estimation of the household production, and the demand-supply approach borrowed from Feenstra's (1994) research on trade elasticities. Both strategies report the estimates are much larger than unit and closer to previous indirect estimates. We show our results are robust when applied to Aguiar and Hurst's (2007) sample, in which they employed the indirect estimation. The larger goods-time EOS indicates policies aiding households with money for groceries like the Supplemental Nutrition Assistance Program (SNAP) are more sufficient, since money for certain groceries can more easily substitute for time in making meals. Chapter 3 explores the elasticity of trade with respect to port congestion time. U.S. ports have struggled with significant supply chain congestion during the past two years. Anecdotal evidence shows the increasing port congestion brought substantial losses to U.S. exports, particularly agricultural shipments. However, previous studies are limited by the availability of explicit data on congestion times for unloading. This study first quantifies the association between port congestion days and U.S. agricultural exports, using monthly export data of top U.S. ports and their monthly average container and bulk shipments delays. We find one extra day delay of container shipments decreases U.S. agricultural monthly exports by 5 percent in quantity or 2 percent in value on average. That amounts to $63 million in monthly loss of export value on average, and Western U.S. ports are responsible for 69 percent of this total. The effect is most pronounced for the Western U.S. exports of bulk commodities, where congestion results in a 9 percent loss in quantity or 8 percent loss in value. For Eastern U.S., the most salient effect is on consumer commodities, with a loss of 3 percent in quantity and 3 percent in value. For the Gulf region, the largest effect is on bulk commodities, with a loss of 4 percent in quantity and 5 percent in value. The impacts of congestion on bulk shipments are both statistically and economically insignificant. However, we find some evidence that exporters substitute bulk cargoes with containers when bulk shipment delays at ports increase. The substitution of container shipments with bulk shipments, however, is unlikely.
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    Evaluating Cost Effectiveness of the USDA's Expanded Food and Nutrition Education Program
    Baral, Ranju (Virginia Tech, 2013-08-05)
    The Expanded Food and Nutrition Education Program (EFNEP) is one of the largest efforts of the US Department of Agriculture (USDA) to promote healthy dietary behavior practices among the low income adults and youths in the US. Although the program is shown to be effective in achieving its stated goals, the cost effectiveness of the money spent on EFNEP remains largely unknown. This dissertation analyzes the costs and effectiveness of the EFNEP, and is organized in three essays. The first essay investigates the effectiveness of the adult EFNEP and evaluates the returns to scale on the money spent in this program by utilizing an indirect production function approach. Results indicate that the program has increasing returns to scale at the National level, although a significant variation exists across the states. The second essay develops a framework for conducting the cost effectiveness analysis (CEA) for the youth EFNEP. The CEA framework is then applied to the data from Virginia youth EFNEP to estimate the cost effectiveness ratio (CER). The CER is estimated to be about $75 per behavior improvement. The third essay examines the outcomes and the attributes of the youth EFNEP program using the Rasch model type measurement model.  Findings suggest that the youth EFNEP is effective in achieving its stated program goals. In addition, the program related characteristics are found to be important attributes of effective programs. Overall, this dissertation has important policy implications for improving the (cost) effectiveness of nutrition education programs. "
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    Evaluation of Food Assistance Programs and Implications of Patients' Health Information Seeking
    Li, Yiran (Virginia Tech, 2013-12-16)
    The first part of this dissertation evaluates the effectiveness of food assistance by gathering evidence from developing countries and the United States. The first essay applies a multi-market model to three developing countries and simulate recent spikes in staple prices and food aid impacts. Results indicate that higher food prices would result in reduction in household real income and deterioration of household welfare. Food aid in the form of cash transfers targeted at low-income groups could improve household real income of the target group after world price shocks and, partially or completely, offset the negative impacts of higher food prices. The impact of cash transfer on untargeted groups is ambiguous. It is likely to be positive for households that are net producers of the commodities that have increased production and prices under cash transfer and the production surplus is sufficiently large. The second essay focuses on the Food Stamp Program (FSP), a cornerstone of food assistance safety net efforts in the U.S. to reduce household food insecurity, particularly among children. The essay examines the dynamic relationship between FSP participation and child food security using monthly measures. Empirical estimates using the Panel Study of Income Dynamics demonstrate that child food security declines in the months immediately prior to FSP entrance, but then partially recovers following program entrance. These dynamic FSP effects are masked when annual measures are employed. The third paper of this dissertation studies the potential impacts of patient's widespread use of online health information. In particular, the essay employs a principal agent model and focuses on the quality of online health information. The model shows that when the quality of health information improves, since medical consultations become more efficient and less costly, a higher effort will be induced or contracted from the physician. Diagnosis becomes more accurate, because physicians will try exert more effort in diagnosing patients and patients will suffer less loss from their illnesses.
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    An Examination of Virginia's Adult SNAP-Ed Program by Cost-Effectiveness Using Program Cost and Participant Self-Evaluations
    Strayer, Thomas Edward III (Virginia Tech, 2015-08-31)
    The Supplemental Nutrition Assistance Program Education (SNAP-Ed) is an extension of the Supplemental Nutrition Assistance Program (SNAP) that aims to promote living healthier lifestyles for low-income participants of SNAP with limited resources. This thesis aims to investigate the effectiveness of Virginia's adult SNAP-Ed program through a cost-effective analysis (CEA) for fiscal year 2013 which requires the separation of the into the costs and the effects of the program. The costs for the program are categories as the labor, capital, material, and utility costs that are required to implement the adult SNAP-Ed program. The effects are measured as the number of participants who start, graduate, and improve from the start to the end of the program. The effects were measured on a retrospective self-assessment that measured both if a participant graduated and their magnitude of improvement. The analysis showed that as the state of Virginia the adult SNAP-Ed program incurred a cost of $2,488,170.07 with 6,759 participants starting the program and 3,704 of those that graduated in fiscal year 2013. Participants that improved on at least one of the questions by a score of one were 3,609 of the 3,704 that graduated. For the state of Virginia the cost effective ratio (CER) for starting a participant was $368 and CER of $672 for each graduated participant. An improvement on at least one question saw a CER value of $689. These findings show patterns that can be used for future policy implementation and the focus of the program.
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    Exploring Alternative Methodologies for Robust Inferences: Applications in Environmental and Health Economics
    Kaul, Sapna (Virginia Tech, 2013-10-24)
    Researchers often invoke strong assumptions in empirical analyses to identify significant statistical outcomes. Invoking assumptions that do not sufficiently reflect the occurrence of true phenomenon reduces the credibility of inferences. Literature suggests that the potential effects of assumptions on credibility of inferences can be mitigated by comparing and combining insights from alternative econometric models. I use this recommendation to conduct robustness checks of commonly used methods in environmental and health economics. The first chapter proposes a novel nonparametric regression model to draw credible insights from meta-analyses. Existing literature on benefit-transfer validity is examined as an application. Nonparametric regression is found to be a viable approach for drawing robust policy insights. The second chapter proposes an alternative structural and simulations based framework to understand elicitation effects in survey response data. This analysis explains the structural mechanisms in which response anomalies occur and is important for building credible insights from survey data. The last chapter uses methods in program evaluation to investigate the impacts of institutional child deliveries on long-term maternal health in the context of developing countries. The outcomes of this analysis indicate that institutional deliveries positively affect maternal health in lower socio-economic states. Based on the findings of my three chapters, I recommend that researchers should combine insights from alternative models to mitigate the scope of specification bias in empirical outcomes and inform policy about the potential uncertainty that arises in uncovering the truth using statistical methods.
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    Factors influencing high respiratory mortality in coal-mining counties: a repeated cross-sectional study
    Shi, Ruoding; Meacham, Susan; Davis, George C.; You, Wen; Sun, Yu; Goessl, Cody (2019-11-08)
    Background Previous studies have associated elevated mortality risk in central Appalachia with coal-mining activities, but few have explored how different non-coal factors influence the association within each county. Consequently, there is a knowledge gap in identifying effective ways to address health disparities in coal-mining counties. To specifically address this knowledge gap, this study estimated the effect of living in a coal-mining county on non-malignant respiratory diseases (NMRD) mortality, and defined this as “coal-county effect.” We also investigated what factors may accentuate or attenuate the coal-county effect. Methods An ecological epidemiology protocol was designed to observe the characteristics of three populations and to identify the effects of coal-mining on community health. Records for seven coal-mining counties (n = 19,692) were obtained with approvals from the Virginia Department of Health Office of Vital Statistics for the years 2005 to 2012. Also requested were records from three adjacent coal counties (n = 10,425) to provide a geographic comparison. For a baseline comparison, records were requested for eleven tobacco-producing counties (n = 27,800). We analyzed the association of 57,917 individual mortality records in Virginia with coal-mining county residency, county-level socioeconomic status, health access, behavioral risk factors, and coal production. The development of a two-level hierarchical model allowed the coal-county effect to vary by county-level characteristics. Wald tests detected sets of significant factors explaining the variation of impacts across counties. Furthermore, to illustrate how the model estimations help explain health disparities, two coal-mining county case studies were presented. Results The main result revealed that coal-mining county residency increased the probability of dying from NMRD. The coal-county effect was accentuated by surface coal mining, high smoking rates, decreasing health insurance coverage, and a shortage of doctors. In Virginia coal-mining regions, the average coal-county effect increased by 147% (p-value< 0.01) when one doctor per 1000 left, and the effect increased by 68% (p-value< 0.01) with a 1% reduction of health insurance rates, holding other factors fixed. Conclusions This study showed a high mortality risk of NMRD associated with residents living in Virginia coal-mining counties. Our results also revealed the critical role of health access in reducing health disparities related to coal exposure.
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    Food Availability and Behavior of Youth EFNEP Participants in Virginia
    Almohanna, Amal Sami (Virginia Tech, 2016-06-03)
    Low-income and minority youth are disproportionately affected by low food access, low dietary quality, and high levels of obesity. The Expanded Food and Nutrition Education Program (EFNEP) is designed specifically to assist limited resource youth and adult audiences to acquire the knowledge, skills, attitudes, and changed behavior necessary for nutritionally sound diets, and to contribute to their personal development and improvement of the overall family diet and nutritional well-being by using a peer-education model (USDA, 2012). To date, little published research exists on dietary patterns and food access among youth who participated in EFNEP. The specific research goals of this study were to: 1) explore baseline dietary and physical activity self-efficacy and behaviors of youth EFNEP participants and compare to national trends, 2) examine differences in self-efficacy and behaviors based on socio-demographic factors and food availability, and 3) determine the association between food availability and dietary behavior. This study consisted of conducting surveys with 1,864 low-income youth, ages 7 to 14 years old, across Virginia prior to participation in an obesity-prevention program. The survey consisted of a 55-item written pre, post-test instrument that had been previously tested for validity and reliability. Most participants reported availability across all food groups, with the exception of meat and beans (41.4%) and dessert (48.3%). Significantly less than half of participants reported not meeting dietary behavior thresholds for the following food groups: grains (27.0%); whole grain (19.7%); low-fat milk (31.5%); vegetables (18.2%); colored vegetables (15.3%); and baked foods (31.7%). Availability of meats and beans and fruits were higher among Latinos than non-Latinos. Younger participants reported a higher consumption of sugar-sweetened beverages and screen time; however, the children had participated in physical activity. Participants who reported a higher availability of fruits and vegetables at home also participated in physical activities at least once a day. This study provided insight into the availability of food, as well as food consumption among low-income audiences across Virginia, based on youth EFNEP reporting. The results highlighted the importance of strategic interventions to improve the availability of nutritious foods and obesity prevention strategies to enhance self-efficacy and intake of nutritious foods among low-income youth.
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    A Grocery Store Intervention Designed to Increase Fruit, Vegetable, and Healthy Snack Purchases among Parents of Young Children
    Holmes, Ashley Shannon (Virginia Tech, 2009-12-16)
    Objective: The aim of this study was to develop and evaluate a 12-week multi-faceted, child-focused intervention that included a point-of-purchase kiosk featuring fresh fruits, vegetables, and healthy grab-and-go snacks; and a sampling pod, comprised of food items from the kiosk. Design: An observational uninterrupted time-series design was used in one intervention grocery store. The intervention consisted of two components, a Healthy Kids Kiosk and food sampling. Subjects/Setting: Patrons of Ukrop's Inc. Grocery store in Roanoke, Virginia. May-September 2009 Measures: The study measures consist of three components: 1) examination of changes in sales data for featured products, provided by the grocery chain; 2) candid, unobtrusive, blind observations of customers near and around the intervention; and 3) brief questionnaires of customers, who engaged at some level with the Kiosk and sampling pod. Results: The results yielded an overall increase in the proportion of the sales of the featured items to total store sales during the intervention period. Individual items that increased sales during the intervention period, included whole-wheat mini bagels, bananas, radishes, honey, sunflower, baked tortilla chips, and almond butter (p<.05). Parents whose children were arguing, crying/whining, or not in the shopping cart, had higher levels of engagement with the kiosk. Almost two-thirds (61.7%) of the patrons interviewed noticed the healthy kids kiosk, with about one-quarter (28.7%) indicating that they purchased at least one item. Fifty-eight percent reported that the kiosk encouraged them to buy healthier foods. Conclusion: Promoting healthy foods at point-of purchase locations can result in increased purchases of these foods among families with young children. Application: These findings have provided insight into the effectiveness of grocery store interventions on purchasing patterns and behaviors of families with young children.
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    The Impact of Bankruptcy Exemptions for Retirement Assets
    Baker, Matthew (Virginia Tech, 2013-05-21)
    When filing for personal bankruptcy, an individual can, in almost all cases, claim an exemption for retirement assets.  Using the Survey of Consumer Finances from 2007 and 2010, we test the theory that highly educated or financially sophisticated households allocate more resources to retirement assets under conditions of higher probability of filing for personal bankruptcy.  This hypothesis stems from the concept of asset sheltering, in which an individual will demonstrate a preference for assets that are exempt from a particular risk. To address our hypothesis, we run a Heckman model on the Survey of Consumer Finances data.  Our results provide evidence to match our theory for only highly educated or financially sophisticated individuals, conditional on owning retirement assets.  That is, we observe highly educated and financially sophisticated households allocate more resources to retirement accounts when they are at higher risk for bankruptcy.  Other characteristic groups do not demonstrate a similarly strong relationship between the probability of filing for bankruptcy and the level of retirement assets.
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    Incorporating Food-away-from-Home into the Thrifty Food Plan
    Zhang, Ge (Virginia Tech, 2008-08-12)
    This study explores the impact of incorporating Food-away-from-Home (FAFH) into the Thrifty Food Plan (TFP). The new model of this study, FLEX, uses similar sets of datasets on prices, nutrition and average consumption pattern as those used in the TFP model. The 2001-2002 National Health and Nutrition Examination Survey (NHANES) data is used to generate average consumption and nutrient profiles. The relative price ratio of FAFH to FAH is assumed and fixed at 1.77. We compared nutrient intake, food intake and food expenditure amount across the FLEX, TFP, and the current low-income consumers' consumption pattern. The overall finding is that moderate amount of FAFH can be a part of a balanced and nutritious diet and allowing FAFH as another food sources makes the diet recommendations relatively easier to follow. With the relative price assumption used in this study, considering FAFH does not make the diet plan unaffordable.