Contagion among countries and sectors when a financial crisis breaks out is currently under scrutiny. The existing literature focuses on establishing the existence of contagion among equity markets but relatively little attention is devoted to examining which channels spread the shock to individual sectors. This study extends the literature by estimating a time-series of contagion for sectors identified as contagious, investigating three potential channels of shock transmission and investigating the role of the channels as the severity of contagion increases. Using data for 16 emerging markets and nine industrial sectors for the 2007-2009 financial crisis, we find that the global channel provides a mechanism that stabilizes and mitigates contagion while the country channel is the primary force encouraging contagion and the sector channel is ineffective. We also find the role of each channel may change as the severity of contagion increases.

During the most recent financial crisis, a myriad of banks defaulted. This scenario encouraged the development of a mathematical model for how default spreads through a system of banks. As we will see, the problem brings together ideas from many fields in Mathematics: Combinatorics, Linear Algebra, Calculus, Statistics and Probabilities. Afterwards, we will turn our attention not only towards implementing the model in MATLAB, but also towards interpreting the results obtained.

This study examines the differences in the provision of non-audit services (NAS) for audit offices that receive SEC Accounting and Auditing Enforcement Releases (AAERs). While prior research examines the links between the provision of non-audit services and impaired auditor independence, less attention has been paid to the contagion effects of independence violations. However, I do not find any evidence of a significant difference in the amount of NAS provided by offices that receive an independence-related AAER, relative to offices that receive other auditor-related AAERs. Broadly, my findings suggest that clients do not differentiate between independence violations and other audit-related violations and that no contagion effect exists for independence violations.

When do children begin to realize that the authenticity of an object is not inherent to an object itself, but instead depends on the information one has about the object in question? In two studies I investigated elementary school children’s reasoning about authenticity violations. How we reason about authenticity violations, or cases in which the purported history of an item is shown to be false, is important in that it provides an example of how people can reason about the underlying, non-obvious features of objects. Participants (N= 64, ages 7-9) were first asked to rate the value of a series of everyday objects using a Likert scale (one to ten). Next, information about the individual history of these objects was presented and participants were asked to re-rate them and provide explanations for their ratings. Using a between-subjects design, participants were then informed that the information they had been given about the objects’ histories was the result of intentional deception (Study One) or a mistake (Study Two) and were again asked to re-rate the objects and provide explanations for their ratings. Results from value ratings and explanations from both studies indicate that elementary school children are sensitive to the authentic nature of objects as well as intentional and accidental violations of authenticity. I propose that reasoning about associative essences, a novel term described in this paper, can be productively examined using violation of authenticity paradigms, providing insight into the development of reasoning about authenticity. / text

Among some haplorhine primates, including humans, relaxed yawns spread contagiously. Such contagious yawning has been linked to social bonds and empathy in some species. However, no studies have investigated contagious yawning in strepsirhines. We conducted an experimental study of contagious yawning in strepsirhines, testing ring-tailed and ruffed lemurs (n = 24) in a paradigm similar to one that has induced contagious yawning in haplorhines. First, in a control experiment, we investigated whether lemurs responded to projected video content in general (experiment 1). We showed them two videos to which we expected differential responses: one featured a terrestrial predator and the other a caretaker holding food. Next, to test for yawn contagion, we showed individual lemurs life-size video projections of groupmates and conspecific strangers yawning, and control footage of the same individuals at rest (experiment 2). Then, to examine whether a group context might enhance or allow for contagion, we exposed subjects to the same videos in a group setting (experiment 3). Lemurs produced alarm vocalizations and moved upward while viewing the predator, but not the caretaker, demonstrating that they do perceive video content meaningfully. However, lemurs did not yawn in response to yawning stimuli when tested alone, or with their groupmates. This study provides preliminary evidence that lemurs do not respond to yawning stimuli similarly to haplorhines, and suggests that this behavior may have evolved or become more exaggerated in haplorhines after the two major primate lineages split.

This research aims to identify to what extent the primary drivers of migration gain influence due to social contagion effects – in other words, to what extent the metaphor of an “epidemic” can be used to describe emigration. The scope of the research is limited to the migration of individuals from South Africa to countries abroad. A model is developed as a means with which to analyse the premise that social contagion influences migration due to its effect on the underlying driver's thereof. Results obtained through analysis of secondary data reveal the primary drivers of migration, their trends and their relative influence within the population. Results obtained through simulation revealed that the impact of general crises attributable to a particular determinant of migration is fleeting and that increased rates will subside in time. In contrast, as random isolated events related to the primary drivers of migration increase in frequency and intensity, so too does migration. In addition, drivers disseminated through social contagion discouraging migration from South Africa are found to be capable of negating the influence of the determinants of migration. Copyright / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

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This dissertation consists of three essays studying human behavior and contagion phenomenon in networks. The analysis especially focuses on information sharing, trade relationship and pest spread in networks. The first chapter outlines the dissertation by briefly discussing the motivations, methods, and main findings in each of the following chapters. Chapter two examines the information sharing in networks. We develop a heterogenous agents model in which connections between players act as a channel to exchange information. We focus on specialized equilibria, which is based on Nash tatonnement. It is shown that players utilize the signals in the linear form and only specialized equilibria can be stable. We also compare the sequential equilibria and stable equilibria, and it is shown that stable equilibria form a proper subset of the sequential ones, which gives a sharper prediction. The stable equilibria demonstrate star-like graphs, which is similar to the phenomenon "the law of the few" in the literature. Chapter three investigates the trade relationship among players where trade between two players can bring benefits as well as conflict. And if conflict happens, the players coordinate based on received information. We show that the optimal structure of trade networks ranges from complete market to Autarky. Also, we study the optimal timing for trade relationship establishment and the optimal size of organizations when facing scarce members. It is shown that when potential neighbors become more scarce, people care more about the future, or new technology breakthroughs occur more frequently, it is optimal to have more neighbors to back up for the potential technological breakthrough. The last chapter studies the pest spread in the networks. We use a directional and weighted network to study the spread of Tuta absoluta. A robust network-based approach is proposed to model seasonal flow of agricultural produce and examine its role in pest spread. Furthermore, the long-term establishment potential of the pest and its economic impact on the country are assessed. Preliminary analyses indicate that Tuta absoluta will invade most major tomato production regions within a year of introduction and the economic impact of invasion could range from $17-25 million. / Ph. D. / Networks play an important role in the society today, for example, the Internet, Facebook and other social media, cell phones, and communication networks. Networks have undeniable effects on human activity in modern society and this dissertation will focus on three topics: information sharing in networks, trade networks and diffusion in the networks. Information sharing in networks: In the society, individuals have different ability to refine signals, so their strategy about information will be different. In this paper, we assume that there are noisy signals about the true state of the world and individuals have a tradeoff between refining their signals by themselves and connecting to others to receive information. It is shown that players utilize the signals in the linear form and only specialized equilibria can be stable. Furthermore, the stable equilibria demonstrate star-like graphs, which is similar to the phenomenon “the law of the few” in the literature. The structure of trade networks: Trade is ubiquitous in modern society and has undeniable effects on human activity. The trade relationship among players can bring benefits as well as conflict. Facing the advantages and disadvantages of trade, players need to make decisions about who to trade with. We show that the optimal structure of trade networks ranges from complete market to Autarky as economy environment changes. Also, we study the optimal timing for trade relationship establishment and the optimal size of organizations when facing scarce members. It is shown that when potential neighbors become more scarce, people care more about the future, or new technology breakthroughs occur more frequently, it is optimal to have more neighbors to back up for the potential technological breakthrough. Diffusion in networks: Diffusions like information, diseases, rumor are usually through the network in the society. We study the pest spread Nepal in the networks. Based on road networks and trade patterns, we model the flow networks of the pest spread. Based on the flow network, the long-term establishment potential of the pest and its economic impact on the country are assessed. Preliminary analyses indicate that Tuta absoluta will invade most major tomato production regions within a year of introduction and the economic impact of invasion could range from $17-25 million.

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The “seeds of disease” theory that emerged in Europe during the Renaissance period was not an entirely novel concept at the time. Humans were aware of the contagious properties of certain afflictions long before it was possible for them to observe the microorganisms responsible for disease transmission, and ancient authors had already speculated about the existence of imperceptible creatures as a cause of illness. This thesis will show that through ancient literary works of every type permeates the recognition of disease contagion not only between humans, but also between animals of the same species, animals of different species and between humans and animals. Chapter One will examine cases of intra-species infection, beginning with those that do not specify precisely the manner in which the illness in question is passed from one being to another. Instances in which particular factors are noted as contributing to the spread of disease will also be presented, followed by examples highlighting the recognition of intra-species infection in animals. Chapter Two will address the three varieties of inter-species infection of which ancient people were evidently aware: zoonosis, anthroponosis, and xenoosis. Chapter Three will explore the prevalent belief among the ancients that uninterred corpses incited pestilences. Chapter Four will discuss ancient views concerning the contamination of drinking water, as well as cases of deliberate infection with disease— ancient precursors to bioterrorism. Chapter Five will feature numerous theories of ancient authors regarding the presence of disease-causing microorganisms in the air. A variety of literary evidence will be examined throughout this paper and will prove that there was indeed a pervasive knowledge of disease contagion in the ancient world. / Thesis (Master, Classics) -- Queen's University, 2013-09-09 09:27:06.882