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This research presents a bi-level stochastic network interdiction model on an attack graph to enable a risk-averse resource constrained cyber network defender to optimally deploy security countermeasures to protect against attackers having an uncertain budget. This risk-averse conditional-value-at-risk model minimizes a weighted sum of the expected maximum loss over all scenarios and the expected maximum loss from the most damaging attack scenarios. We develop an exact algorithm to solve our model as well as several acceleration techniques to improve the computational efficiency. Computational experiments demonstrate that the application of all the acceleration techniques reduces the average computation time of the basic algorithm by 71% for 100-node graphs. Using metrics called mean-risk value of stochastic solution and value of risk-aversion, numerical results suggest that our stochastic risk-averse model significantly outperforms deterministic and risk-neutral models when 1) the distribution of attacker budget is heavy-right-tailed and 2) the defender is highly risk-averse.

Previous studies have underscored the economic importance of the role of the entrepreneur, and empirical studies testing the nature of the entrepreneur are notably lacking. This study directly addresses this issue by examining newly gathered field data which captures the decision making and risk behaviors for a group of high-technology entrepreneurs. Two decision making tasks were used to elicit risk aversion measures and to test for any 'joy of winning' or judgmental errors, possibly in the form of over optimistic behavior. These elicitations were made with the use of multiple price formats and winner's curse experiments. 62 responses were collected from subjects at the 2004 national Small Business Innovation Research (SBIR) conference in Atlanta, March 2004. From these 62 responses a subject pool of 33 entrepreneurs and 29 non-entrepreneurs were identified. Statistical methods were employed to assign risk aversion measures and identify any 'joy of winning' or judgmental errors for the entrepreneur (treatment) group compared with the non-entrepreneur (control) group. Findings show that entrepreneurs exhibit less risk aversion, but show no statistically meaningful difference in judgmental errors compared to their non-entrepreneur counterparts. However, there is evidence to support the claim that both entrepreneurs and non-entrepreneurs exhibit a 'joy of winning', and that the size of the effect is larger for entrepreneurs.

Children have an early-emerging expectation that resources should be divided fairly amongst agents, yet their behavior does not begin to align with these expectations until later in development. This dissociation between knowledge and behavior raises important questions about the mechanisms that encourage children to behave how they know they should behave. Here I tested whether explicitly invoking fairness norms encourages costly fair decisions in 4- to 9-year-old-children. I examine children’s responses to unequal resource allocations in the Inequity Game by varying the direction of inequity (advantageous versus disadvantageous inequity) and normative information (to be fair or to act autonomously). The results show children are more likely to reject advantageous allocation in the Fairness norm condition than in the Autonomous norm condition, but I did not see this difference when children are presented with disadvantageous allocations. This study showcases children’s costly fairness norm enforcement as a flexible process, one that can be brought in and out of alignment with their knowledge of fairness by shining a spotlight on how one ought to behave.

The abuse of alcohol is a complex behavior pattern exhibited by approximately nine million people in this country (Tarter & Sugarman, 1976) and has become a field of interest to science, industry, and the helping professions. Estimates of spontaneous recovery among alcoholics vary drastically. In 1971 the National Institute on Alcohol Abuse and Alcoholism began sponsorship of a comprehensive alcoholism treatment program located in 45 community centers throughout the nation. Using a multiple criterion measure of improvement, their report (Rand Corporation, 1976) estimated the rate of spontaneous improvement for alcoholics to be as high as 53%. In reviewing the rates of spontaneous improvement from a number of studies, Baekland (1977) states, "It thus appears that depending on the patient's personal and social assets, there is a 2-15% spontaneous improvement rate in alcoholics who do not receive formal treatment" (P 390). Unlike the Rand Report, Baekland used total abstinence ·as the measure of spontaneous improvement. The present study sought to compare the relative effectiveness of group administered covert sensitization with traditional insight-oriented group therapy in treating alcoholism. To control for the effects of relaxation training, therapist contact, favorable outcome expectancy, and the act of imaging (variables inherent in the covert sensitization procedure but not controlled for in the previously cited outcome studies), a relaxation placebo control group was employed which was empirically evaluated for its credibility. It was hypothesized that subjects in all three groups would show significant improvement over time on each of the dependent measures, and that subjects receiving covert sensitization would show significantly greater improvements than subjects receiving traditional group therapy or the relaxation placebo treatment. No differences were expected between group therapy and the relaxation placebo treatment.

[pt] Este artigo estuda disparidades de gênero no desempenho e na aversão ao risco sob competição. Utilizamos dados do Exame Anpec, exame de seleção nacional de candidatos aos cursos de mestrado (e doutorado) em Economia no Brasil. Este exame específico atribui pontos negativos a respostas incorretas, o que pode fazer com que os alunos mais avessos ao risco deixem mais perguntas sem resposta e possivelmente obtenham notas mais baixas. Mostramos que as mulheres tendem a omitir mais perguntas em comparação com os homens e estão consistentemente sub-representadas no topo dos rankings. Utilizando o Modelo Rasch derivamos probabilidades de cada aluno responder cada questão corretamente e mostramos que tanto homens como mulheres se desviam da estratégia ótima que maximiza a nota esperada. Investigamos também o cenário onde todos os alunos chutam as questões anteriormente deixadas em branco, após recalcular as notas esperadas e novas classificações neste cenário mostramos que em média o efeito para as mulheres que já estavam no topo da distribuição é muito pequeno, e as mulheres que estavam com classificação mais baixa se beneficiam mais. / [en] This paper studies gender disparities in performance and risk aversion under competition. We use data from the Anpec Exam, the Brazilian national exam for students applying for Graduate Programs in Economics. This particular exam assigns negative points to incorrect answers, which could lead to the more risk-averse students leaving more questions unanswered and possibly getting lower grades. We show that women tend to omit more questions compared to men and are consistently under represented at the top of the rankings. Using the Rasch Model we derive probabilities of answering each question correctly for each student and show that both men and women deviate from the optimal strategy that maximizes their expected score. We also investigate the scenario where all students guess the questions previously left unanswered, after recalculating the expected scores and new rankings in this scenario we find that on average the effect for women that were already at the top of the distribution is very small, and women that were closer to the bottom of the ranking benefit more.

Indiana University-Purdue University Indianapolis (IUPUI) / Nicotine addiction is an extremely costly and widespread issue that affects millions of people globally and current treatments have relatively low long term efficacy rates. This demonstrates the need for a greater understanding of nicotine addiction and its underlying mechanisms. This study created a C. elegans model of compulsive nicotine use. C. elegans, that were pretreated with nicotine (9.7 μM or 120 μM) from larval stage 4 to gravid adulthood, demonstrated reduced aversion to 10% nonanone in the presence of nicotine compared to untreated worms. The pretreatment concentration of 9.7 μM nicotine was chosen for further study due to its ability to induce aversion resistance without significant changes to locomotor speed, food preference, or benzaldehyde preference. This model was then applied to nicotinic acetylcholine (acr-5, acr-15, acr-16) and dopamine (dop-1, dop-2) receptor knockout mutants to determine the roles of these receptors in the development of aversion resistance. For the acr-5, acr-15, and acr-16 mutants, there was an increase in preference following the administration of 10% nonanone, regardless of pretreatment condition, suggesting that the removal of these receptors induces aversion resistance. For the dop-1 receptor mutant, 10-minute timepoint nicotine preference was reduced following preexposure. For the dop-2 receptor mutant, aversion was enhanced at the 5 mM and 50 mM test concentrations following the administration of 10% nonanone, suggesting that the dop-2 receptor is partially responsible for the development of aversion resistance. Additional research should be conducted to determine the underlying mechanisms of this drug induced aversion resistance. With current the lack of highly efficacious nicotine cessation drugs, this model could be used to test novel therapeutic drugs in a rapid high throughput manner.

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Individuals' decisions to adopt an innovation can be influenced by the group identity of previous adopters or non-adopters in their social network. Previous research in innovation diffusion considered initial innovators and word-of-mouth imitator effects using analytical models. Simulations and agent-based models have been developed to address the heterogeneity of decision makers and the non-linearity of the process. A further refinement modeled adoption based on networks of social relationships between potential decision makers, analogous to the spread of disease on networks. In addition, adoption or non-adoption of some innovations has been characterized as a means of signaling identification with or aversion to a group. While identity signaling and outgroup aversion effects on adoption have been considered in a geo-spatial environment, this work extends these concepts to social network environments. The results show that adoption levels were significantly different in a network environment with outgroup effects present. Additionally, as outgroup and imitation factors increase, adoption levels decrease, and polarization increases in network environments. With group effects present, adoption was found to be higher when modularity and eigenvector centrality are high in a social network. Next, to test the model, Covid-19 vaccination adoption behavior was examined to find statistical evidence of the outgroup effect with groups defined by political affiliation. Finally, a model was developed to address gaps in the original model and evaluated with vaccine adoption data. In today's polarized social environment, understanding these effects is critical to the adoption of emerging innovations such as mitigating climate change, combating novel viruses, or decentralizing financial transactions. While innovators are often focused on solving technical challenges to advance adoption of an innovation, equal emphasis on understanding and solving social and potential outgroup effects will be needed to accurately project the rate of adoption and to achieve the desired outcome.

Economic preferences are crucial in decision making. While some preferences remain stable, changes in economic preferences have been linked to institutional and policy changes. We conduct three studies to explore the ways in which decision making might be impacted by economic preferences and underlying or changing policies. Our studies span the domains of preventative healthcare, strategic interactions, and education. Chapter 2 examines the relationship between cooperative decision making and changes in societal level institutions through a meta-meta analysis, incorporating experimental data from various previously conducted meta-analyses. We study the relationship between country or region level policy changes, as measured by economic freedom indices to experimental measures of prosocial and selfish behavior. Our results indicate a relationship between macro-level institutional changes and measures of co-operative behavior that varies based on the starting levels of economic freedom variables. This establishes a relationship between macro policies and individual behavior that suggests that governments should consider the consequences of policies on individual decision making. Chapter 3, using vignette experiments, explores how emotion reappraisal messaging interventions affect betrayal aversion and vaccine hesitancy. The measure of betrayal aversion in our study involves hesitancy in risking being betrayed in situations involving trust related to vaccines. We find that betrayal aversion is prevalent in about a third of our study participants and that two of our messaging interventions substantially reduce betrayal aversion involving vaccination decisions. Our results suggests a targeted messaging strategy for addressing a recently discovered new component of vaccine hesitancy, an important current topic in preventative healthcare. Chapter 4, introduces an active learning intervention in the form of a field experiment involving a health intervention nudge and explores its impact on class engagement and education outcomes of students. In addition, we look at the impact of the nudge on vaccination uptake among students. We find improved class engagement as well as improvement in test scores for students who had the opportunity and chose to participate in the nudge experiment. In addition, we find greater uptake of influenza vaccination, as targeted by the nudge treatment. Our results show that this effect is driven by men, with women having higher vaccination rates irrespective of the nudge treatment. JEL codes: C91, H1, 01, P5, I12, D91, A22, C93 / Doctor of Philosophy / This dissertation explores how policy changes in our environment, interact with our preferences and affect decision making in social decision making, healthcare and education domains. We explore macro policies designed to create country-level institutional changes, involving the legal system, monetary policy, trade and labor policy, as well as examining two individual-level interventions including targeted messaging to improve vaccination uptake, and course performance in introductory economics. These wide variety of policy interventions give us a wide spectrum of decisions to study across different domains. Chapter 2 examines the relationship between policy changes at the macro-institutional level and aggregate cooperative decision making. In this study, we establish a relationship between baseline institutional structure and changes in cooperative behavior corresponding to changes in societal level institutions. Our results suggests that current and historic societal level institutional structures should be kept in mind when designing policies. Chapter 3 explores the effect of messaging treatments targeting emotions on uptake of vaccination using a vignette experiment. Here, we study the effects on a particular emotion, betrayal aversion, which in our study, involves hesitancy related to the risk of getting betrayed in the context of vaccination. Our results suggest that a targeted messaging strategy, might prove to be effective in designing policies to improve vaccination uptake. Chapter 4 explores the impact of an active learning approach on class engagement and education outcomes of students in introductory economics. Providing students the chance to participate in a field experiment designed as a vaccination nudge, we incorporate the active learning component of the course and study the impact of participation in this active learning module. Our results suggest improved engagement and education outcomes among students who had the opportunity to participate in the experiment. Our results also suggest that proximity nudges might prove to be effective in improving vaccination uptake. We demonstrate the importance of designing context-specific policies for them to be instrumental in bringing about targeted change. At the aggregate country level, we find that similar type of policy interventions when introduced in countries with differing baseline institutional structures might lead to different results. At the individual level, we find evidence that targeted interventions does shape decisions. We find that targeted health communications messaging can lead to improvement in health behavior. We also find that introducing active learning modules improves learning outcomes among students. Taken together, the findings in this dissertation demonstrates how both economic preferences and underlying policies are important factors in decision making.