Browsing by Author "Shi, Ruoding"

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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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    Costs of Futures Hedging in Corn and Soybean Markets
    Shi, Ruoding; Isengildina-Massa, Olga (2021)
    This study develops a comprehensive framework to measure, explain and anticipate the costs of futures hedging. Using historical futures prices and margin requirements, we simulate hedging costs for corn and soybeans over 2004-2018. Empirical distributions derived from the simulation results provide unconditional estimates of the costs of hedging as well as the probability of hedging failure. Conditional estimates assess the impact of margin requirements, price volatility and price changes as well as seasonal patterns using quantile regressions. Our findings demonstrate that price volatility is a main driver of the costs of hedging and can be used to anticipate future hedging costs.
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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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    Potential impact of 5 years of ivermectin mass drug administration on malaria outcomes in high burden countries
    Marathe, Achla; Shi, Ruoding; Mendez-Lopez, Ana; Hu, Zhihao; Lewis, Bryan L.; Rabinovich, Regina; Chaccour, Carlos J.; Rist, Cassidy (2021-11)
    Introduction The global progress against malaria has slowed significantly since 2017. As the current malaria control tools seem insufficient to get the trend back on track, several clinical trials are investigating ivermectin mass drug administration (iMDA) as a potential additional vector control tool; however, the health impacts and cost-effectiveness of this new strategy remain unclear. Methods We developed an analytical tool based on a full factorial experimental design to assess the potential impact of iMDA in nine high burden sub-Saharan African countries. The simulated iMDA regimen was assumed to be delivered monthly to the targeted population for 3 months each year from 2023 to 2027. A broad set of parameters of ivermectin efficacy, uptake levels and global intervention scenarios were used to predict averted malaria cases and deaths. We then explored the potential averted treatment costs, expected implementation costs and cost-effectiveness ratios under different scenarios. Results In the scenario where coverage of malaria interventions was maintained at 2018 levels, we found that iMDA in these nine countries has the potential to reverse the predicted growth of malaria burden by averting 20-50 million cases and 36 000-90 000 deaths with an assumed efficacy of 20%. If iMDA has an efficacy of 40%, we predict between 40-99 million cases and 73 000-179 000 deaths will be averted with an estimated net cost per case averted between US$2 and US$7, and net cost per death averted between US$1460 and US$4374. Conclusion This study measures the potential of iMDA to reverse the increasing number of malaria cases for several sub-Saharan African countries. With additional efficacy information from ongoing clinical trials and country-level modifications, our analytical tool can help determine the appropriate uptake strategies of iMDA by calculating potential marginal gains and costs under different scenarios.