Optimal Capital Requirements in Financial Networks with Fire Sales

I explore and analyze a problem of finding the socially optimal capital requirements for financial institutions considering two distinct channels of contagion: direct exposures among the institutions, as represented by a network and fire sales externalities, which reflect the negative price impact of massive liquidation of assets.These two channels amplify shocks from individual financial institutions to the financial system as a whole and thus increase the risk of joint defaults amongst the interconnected financial institutions; this is often referred to as systemic risk. In the model, there is a trade-off between reducing systemic risk and raising the capital requirements of the financial institutions. The policymaker considers this trade-off and determines the optimal capital requirements for individual financial institutions. I provide a method for finding and analyzing the optimal capital requirements that can be applied to arbitrary network structures and arbitrary distributions of investment returns.

In particular, I first consider a network model consisting only of direct exposures and show that the optimal capital requirements can be found by solving a stochastic linear programming problem. I then extend the analysis to financial networks with default costs and show the optimal capital requirements can be found by solving a stochastic mixed integer programming problem. The computational complexity of this problem poses a challenge, and I develop an iterative algorithm that can be efficiently executed. I show that the iterative algorithm leads to solutions that are nearly optimal by comparing it with lower bounds based on a dual approach. I also show that the iterative algorithm converges to the optimal solution.

Finally, I incorporate fire sales externalities into the model. In particular, I am able to extend the analysis of systemic risk and the optimal capital requirements with a single illiquid asset to a model with multiple illiquid assets. The model with multiple illiquid assets incorporates liquidation rules used by the banks. I provide an optimization formulation whose solution provides the equilibrium payments for a given liquidation rule.

I further show that the socially optimal capital problem using the ``socially optimal liquidation" and prioritized liquidation rules can be formulated as a convex and convex mixed integer problem, respectively. Finally, I illustrate the results of the methodology on numerical examples and

discuss some implications for capital regulation policy and stress testing.

The Effect of Reputation Shocks to Rating Agencies on Corporate Disclosures

This paper explores the effect of credit rating agency’s (CRA) reputation on the discretionary disclosures of corporate bond issuers. Academics, practitioners, and regulators disagree on the informational role played by major CRAs and the usefulness of credit ratings in influencing investors’ perception of the credit risk of bond issuers. Using management earnings forecasts as a measure of discretionary disclosure, I find that investors demand more (less) disclosure from bond issuers when the ratings become less (more) credible. In addition, using content analytics, I find that bond issuers disclose more qualitative information during periods of low CRA reputation to aid investors better assess credit risk. That the corporate managers alter their voluntary disclosure in response to CRA reputation shocks is consistent with credit ratings providing incremental information to investors and reducing adverse selection in lending markets. Overall, my findings suggest that managers rely on voluntary disclosure as a credible mechanism to reduce information asymmetry in bond markets.

Content-aware compression for big textual data analysis

A substantial amount of information on the Internet is present in the form of text. The value of this semi-structured and unstructured data has been widely acknowledged, with consequent scientific and commercial exploitation. The ever-increasing data production, however, pushes data analytic platforms to their limit. This thesis proposes techniques for more efficient textual big data analysis suitable for the Hadoop analytic platform. This research explores the direct processing of compressed textual data. The focus is on developing novel compression methods with a number of desirable properties to support text-based big data analysis in distributed environments. The novel contributions of this work include the following. Firstly, a Content-aware Partial Compression (CaPC) scheme is developed. CaPC makes a distinction between informational and functional content in which only the informational content is compressed. Thus, the compressed data is made transparent to existing software libraries which often rely on functional content to work. Secondly, a context-free bit-oriented compression scheme (Approximated Huffman Compression) based on the Huffman algorithm is developed. This uses a hybrid data structure that allows pattern searching in compressed data in linear time. Thirdly, several modern compression schemes have been extended so that the compressed data can be safely split with respect to logical data records in distributed file systems. Furthermore, an innovative two layer compression architecture is used, in which each compression layer is appropriate for the corresponding stage of data processing. Peripheral libraries are developed that seamlessly link the proposed compression schemes to existing analytic platforms and computational frameworks, and also make the use of the compressed data transparent to developers. The compression schemes have been evaluated for a number of standard MapReduce analysis tasks using a collection of real-world datasets. In comparison with existing solutions, they have shown substantial improvement in performance and significant reduction in system resource requirements.

La protection de la vie privée au temps de la biosécurité

Cette thèse s’intéresse à la protection de la vie privée informationnelle dans le contexte de la biosécurité. La biosécurité se définit comme le processus qui vise à prendre en charge, dans une optique de sécurité nationale, les menaces et dangers que représentent les épidémies de maladies infectieuses pour la santé des populations humaines et la sécurité de l’État. Notre projet remet en question l’idée selon laquelle la conduite des activités de surveillance de la santé publique implique nécessairement une diminution de la protection offerte aux renseignements personnels sur la santé. Nos recherches tendent à démontrer que la conciliation de la surveillance de la santé et la protection de la vie privée est non seulement possible, mais qu’elle est surtout nécessaire. Nous portons plus précisément notre attention sur le cas de la collecte et de l’utilisation de renseignements dépersonnalisés sur la santé par les systèmes de surveillance syndromique. Bien calibrée et soigneusement réglementée, cette forme novatrice et particulière de surveillance offrirait le double avantage de réduire les risques d’atteintes à la vie privée des individus et d’augmenter de manière considérable l’efficacité des capacités étatiques en matière de détection des épidémies.

Estrategias resilientes ante la situación adversa de los desahucios

Los desahucios en España se han convertido en los últimos años en un fenómeno social emergente, de interés tanto para la investigación como para la intervención de los profesionales de la acción social. Aun así, no existen estudios suficientes relacionados con esta situación adversa, y menos aún centrados en las respuestas resilientes que las personas son capaces de ofrecer ante ella. Con el objetivo de identificar los factores internos y externos que se presentan en la experiencia de las familias que viven procesos de desahucios y que les están permitiendo desarrollar estrategias resilientes ante dicha adversidad, se lleva a cabo la presente investigación en la que participan 20 sujetos, pertenecientes a familias que acuden a la Plataforma de Afectados por las Hipotecas (PAH) de Málaga. A los participantes se les realiza una entrevista semi-estructurada y a través de ellas se han podido definir las características socio-familiares de las personas afectadas, las diferentes estrategias de afrontamiento desarrolladas, las principales fuentes de apoyo con las que han contado, así como las preocupaciones que les han acompañado. Los resultados muestran los principales factores internos y externos que están presenten en las estrategias resilientes que han desarrollado las familias afectadas por los desahucios durante el proceso vivido y destacan como fuente de apoyo informacional a la PAH. Se concluye con la necesidad de continuar con esta línea de investigación para tratar de diseñar intervenciones que refuercen y fomenten las estrategias de afrontamiento ante la situación adversa del desahucio.

Questioning the merits and demerits of electronic communication in Social Work

This paper examines the social dynamics of electronic exchanges in the human services, particularly in social work. It focuses on the observable effects that email and texting have on the linguistic, relational and clinical rather than managerial aspects of the profession. It highlights how electronic communication is affecting professionals in their practice and learners as they become acculturated to social work. What are the gains and losses of the broad use of electronic devices in daily lay and professional, verbal and non-verbal communication? Will our current situation be seriously detrimental to the demeanor of future practitioners, their use of language, and their ability to establish close personal relationships? The paper analyzes social work linguistic and behavioral changes in light of the growth of electronic communication and offers a summary of merits and demerits viewed through a prism emerging from Baron’s (2000) analysis of human communication.

Sistemas curriculares para la gestión de información y conocimiento institucional. Estudio de caso

La organización del conocimiento en el contexto de las Ciencias de la Información tiene como esencia la información y el conocimiento debidamente documentado o registrado. La organización del conocimiento como proceso, envuelve tanto la descripción física como de los contenidos de los objetos informacionales. Y el producto de ese proceso descriptivo es la representación de los atributos de un objeto o conjunto de objetos. Las representaciones son construidas por lenguajes elaborados específicamente para los objetivos de la organización en los sistemas de información. Lenguajes que se subdividen en lenguajes que describen el documento (el soporte físico del objeto) y lenguajes que describen la información (los contenidos).A partir de esta premisa la siguiente investigación tiene como objetivo general analizarlos sistemas de Gestión de Información y Conocimiento Institucional principalmente los que proponen utilizar el Currículum Vitae del profesor como única fuente de información, medición y representación de la información y el conocimiento de una organización. Dentro delos principales resultados se muestra la importancia de usar el currículo personal como fuente de información confiable y normalizada; una síntesis de los principales sistemas curriculares que existen a nivel internacional y regional; así como el gráfico del modelo de datos del caso de estudio; y por último, la propuesta del uso de las ontologías como principal herramienta para la organización semántica de la información en un sistema de gestión de información y conocimiento.

Hemeroteca digital temática: socialização da informação em cinema

MEDEIROS, Rildeci; MELO, Erica S. F.; NASCIMENTO, M. S. Hemeroteca digital temática: socialização da informação em cinema.In:SEMINÁRIO NACIONAL DE BIBLIOTECAS UNIVERSITÁRIAS,15.,2008,São Paulo. Anais eletrônicos... São Paulo:CRUESP,2008. Disponível em: http://www.sbu.unicamp.br/snbu2008/anais/site/pdfs/3018.pdf

Impacto das tecnologias digitais nas bibliotecas universitárias: reflexões sobre o tema

MOREIRA, Luciana Moreira; SILVA, Armando Malheiro da. Impacto das tecnologias digitais nas bibliotecas universitarias: reflexões sobre o tema. Informaçao e sociedade: estudos. Joao Pessoa, v.19, n.3, p. 125-132,2009.

O cordel como fonte de informação: a vivacidade dos folhetos de cordeis no Rio Grande do Norte

GAUDENCIO, Sale Mario; BORBA, Maria do Socorro de Azevedo. O cordel como fonte de informaçao: a vivacidade dos folhetos de cordeis no Rio Grande do Norte. Biblioonline, Joao Pessoa, v.6, n. 1, p.82-92, 2010.

O paradigma tecnológico e a revolução informacional: fundamentos da sociedade da informação

REGIS, Josiana Florencio Vieira; CAMPOS, Ana Celia Cavalcanti Fernandes. O paradigma tecnologico e a revoluçao informacional: fundamentos da sociedade da informaçao. In: CONGRESSO INTERNACIONAL EM SISTEMAS DE INFORMAÇAO E GESTAO DA TECNOLOGIA, 6., 2009. Sao Paulo. Anais eletronicos... Sao Paulo: FEA/USP, 2009. Trabalho oral.

Socializing toddlers : autonomy-supportive parenting practices and potential risk factors

Selon la théorie de l’auto-détermination, l’autonomie est un besoin universel de base qui, lorsque soutenu, permet aux individus de mieux fonctionner et de vivre plus de bien-être psychologique (p. ex., Deci & Ryan, 2008). Le style parental des parents qui soutiennent l’autonomie de leur enfant est caractérisé par le soutien du fonctionnement autodéterminé de ce dernier. Sa définition traditionnelle inclut des pratiques telles qu’offrir des explications et des choix lors des requêtes, communiquer de l’empathie, et encourager les prises d’initiatives tout en minimisant l’utilisation d’un langage contrôlant (p. ex., Soenens et al., 2007). Les bénéfices d’un style parental qui soutient l’autonomie d’un enfant ont été bien documentés (p. ex., Grolnick, Deci, & Ryan, 1997), toutefois, peu d’études ont été effectuées auprès des bambins. Or, cette thèse visait à enrichir la littérature sur le « parentage » en explorant les pratiques soutenantes qui sont utilisées par des parents de bambins dans un contexte de socialisation (étude 1), ainsi qu’en examinant les facteurs qui peuvent brimer leur mise en pratique (étude 2). La première étude a examiné un grand nombre de pratiques de socialisation que les parents qui favorisent davantage le soutien à l’autonomie (SA) pourraient utiliser plus fréquemment lorsqu’ils font des demandes à leurs bambins. Cette étude nous a permis d’explorer comment les parents manifestent leur SA et si le SA dans ce type de contexte est associé à un plus grand niveau d’internalisation des règles. Des parents (N = 182) de bambins (M âge = 27.08 mois) ont donc été invités à rapporter la fréquence avec laquelle ils utilisent 26 pratiques potentiellement soutenantes lorsqu’ils demandent à leurs bambins de compléter des tâches importantes mais non intéressantes et de rapporter à quel point ils valorisent le SA. Huit pratiques ont été identifiées comme étant soutenantes: quatre façons de communiquer de l’empathie, donner des explications courtes, expliquer pourquoi la tâche est importante, décrire le problème de façon informative et neutre, et mettre en pratique le comportement désiré soi-même. De plus, l’ensemble des huit pratiques corrélait positivement avec le niveau d’internalisation des bambins, suggérant aussi que celles-ci représentent bien le concept du SA. Des études futures pourraient tenter de répliquer ces résultats dans des contextes potentiellement plus chargés ou ébranlants (p. ex., réagir face à des méfaits, avec des enfants souffrant de retard de développement). La deuxième étude a poursuivi l’exploration du concept du SA parental en examinant les facteurs qui influencent la fréquence d’utilisation des stratégies soutenantes dans des contextes de socialisation. Puisque la littérature suggère que le stress parental et le tempérament difficile des bambins (c.-à-d., plus haut niveau d’affectivité négative, plus faible niveau de contrôle volontaire/autorégulation, plus faible niveau de surgency) comme étant des facteurs de risque potentiels, nous avons exploré de quelle façon ces variables étaient associées à la fréquence d’utilisation des stratégies soutenantes. Les buts de l’étude étaient: (1) d’examiner comment le tempérament des bambins et le stress parental influençaient le SA parental, et (2) de vérifier si le stress parental médiait la relation possible entre le tempérament des bambins et le SA parental. Le même échantillon de parents a été utilisé. Les parents ont été invités à répondre à des questions portant sur le tempérament de leur enfant ainsi que sur leur niveau de stress. Les résultats ont démontré qu’un plus grand niveau d’affectivité négative était associé à un plus grand niveau de stress parental, qui à son tour prédisait moins de SA parental. De plus, le stress parental médiait la relation positive entre l’autorégulation du bambin et le SA parental. Des recherches futures pourraient évaluer des interventions ayant pour but d’aider les parents à préserver leur attitude soutenante durant des contextes de socialisation plus difficiles malgré certaines caractéristiques tempéramentales exigeantes des bambins, en plus du stress qu’ils pourraient vivre au quotidien.

Inteligência Emocional e Desempenho Académico em Estudantes do Ensino Superior

A presente investigação examina o papel da inteligêncial emocional (IE) no desempenho académico, numa amostra de 111 estudantes em frequência do ensino universitário português. No presente trabalho faz-se uma revisão bibliográfica do tema da IE e dos factores contributivos para o desempenho académico, bem como uma breve visita a outros trabalhos desenvolvidos nesta área de investigação. Para medição da IE assumiu-se o modelo misto, tendo-se avaliado as seguintes seis dimensões: 1) auto-encorajamento (uso das emoções); 2) compreensão das emoções próprias; 3) autocontrolo perante as críticas; 4)compreensão das emoções dos outros; 5) empatia e contágio emocional; 6) autocontrolo emocional (regulação das emoções). O desempenho académico foi calculado a partir das médias das classificações obtidas pelos estudantes no final do primeiro semestre do ano lectivo 2009/2010. Os resultados evidenciam que os alunos com melhores desempenhos académicos denotam níveis superiores de inteligência emocional, se bem que não foram encontradas associações significativas entre a IE e o desempenho académico, sugerindo a necessidade de mais estudos com vista ao aprofundamento desta jovem e controversa área de pesquisa. / The research investigates the role of emotional intelligence (EI)in academic achivement in a sample of 111 students that attend Portuguese universities. In this work we review the issue of EI and the factors that contibute to academic achievement, at the same time making a brief visit to other works done on this area. In order to measure EI, the mixed model was used, evaluating through the following six dimensions: 1) self-encouragement (use of emotions); 2) understanding of self emotions; 3) self-control in response to criticism; 4) understanding of emotions in others; 5) empathy and emotional contagion; 6) emotional self-control (regulation of emotions). Academic achievement was evaluated by the average of the grades obtained by the students at the end of the first semester of the academic year 2009/2010. The results show that students with better academic outcomes demonstrate higher emotional intelligence, though there were no significative associations between EI and academic achievement, suggesting the need for further studies in order to deepen this young and controversial area of research.

Famílias Unipessoais Idosas: um estudo das redes sociais pessoais de idosos que vivem sós

Objetivos: O presente estudo tem como objetivo analisar as características estruturais, funcionais e relacionais-contextuais das redes sociais pessoais de famílias unipessoais idosas. Metodologia: Utilizámos para recolha de dados um questionário para caracterizar sociodemograficamente a amostra, o Instrumento de Análise da Rede Social Pessoal (versão para idosos) (IARSP-Idosos) (Guadalupe, 2010; Guadalupe e Vicente 2012) e a escala de solidão UCLA (Neto, 1989). Participantes: A amostra é constituída por 567 indivíduos com média de idades de 75,53 anos, maioritariamente do sexo feminino (63,0%; n = 357). Predominam os sujeitos casados (53,7%; n = 304), com filhos (87,8%; n = 498) e em situação de coabitação (n = 450; 79,4%). Contudo, 20,6% (n = 117) vivem sós, constituindo as famílias unipessoais. Resultados: As redes sociais dos idosos têm em média 7,99 elementos, predominantemente familiares (M = 76,89%). Os participantes percecionam um nível elevado de apoio por parte das suas redes. São redes coesas, pouco dispersas e os contactos entre os elementos são frequentes. As mulheres, os indivíduos solteiros, viúvos ou divorciados e os idosos sem filhos têm uma maior probabilidade de viverem sós (p < 0,05) e estes apresentam uma maior probabilidade de necessitar de apoio social formal (p < 0,05). As famílias unipessoais, quando comparadas com os que não vivem sós, apresentam um maior número de campos relacionais e maior proporção de relações de amizade e de vizinhança (p < 0,05). Têm menor perceção de apoio material e instrumental, informativo, companhia social, acesso a novos vínculos e reciprocidade de apoio (p < 0,05). Além disso, referem menor frequência de contactos e uma maior dispersão geográfica (p < 0,05). Nas famílias unipessoais, observou-se a existência de correlações negativas significativas (p < 0,05) entre a percepção de solidão e o tamanho da rede, a proporção das relações familiares na rede, o apoio emocional e informativo e a reciprocidade de apoio. CONCLUSÃO: Os idosos com famílias unipessoais percecionam menor apoio por parte das suas redes, tendo uma maior propensão à solidão. É fundamental, ao longo do ciclo vital, promover a quantidade e qualidade dos vínculos, no sentido de manter a efetividade do suporte das redes mesmo quando se vive só. / Objectives: The present study aims to analyze the structural, functional and relational-contextual characteristics of older single-person households. Methodology: We used as instruments a questionnaire to evaluate sociodemographic data, the Instrumento de Análise da Rede Social Pessoal (version for elderly people: IARSP-Idosos) (Guadalupe, 2010; Guadalupe e Vicente 2012) and the UCLA Loneliness Scale (Neto, 1989). Participants: The sample consists of 567 individuals with an average age of 75.53 years, mostly females (63.0%; n = 357). There is a predominance of married individuals (53.7%; n = 304) with children (87.8%; n = 498). Older people live mainly in cohabitation (n = 450; 79.4%), however 20.6% oh them live alone, constituting one-person households. Results: The elderly personal social networks have 8 elements, on average, with a predominance of family relationships (M = 76.89%). The participants perceived a high level of support from their networks. In general the networks are cohesive, with low dispersion and have frequent contacts. The women, single, widowed or divorced and childless elderly are more likely to live alone (p < 0.05) and to need social services support (p < 0.05). The single-person households, compared with those who do not live alone, have a greater number of relational fields and a higher proportion of friendships and neighborhood relations (p < 0.05). They have a lower perception of material and informative support, social company and acess to new ties and reciprocal support (p < 0.05). They also refer lowest frequency of contacts and a wider geographical dispersion (p < 0.05). In single-person households there was a negative significant correlation between the perception of loneliness and the social network size, the proportion of family relationships in the network, emotional and informational support and reciprocal support. Conclusions: The elderly single-person households perceived less support from their networks and a greater propensity to loneliness. It is critical to promot the quality of ties, rather then their quantity, throughout the life cycle, in order to maintain the network effectiveness even when the person lives alone.

A Família nas Redes Sociais Pessoais de Idosos

Objetivos: Analisar as caraterísticas sociodemográficas e das redes sociais pessoais dos idosos de acordo com a composição das redes centrada na família. Metodologia: Para caraterizar as redes sociais pessoais utilizámos o Instrumento de Análise da Rede Social e Pessoal – Idosos (IARSP-idosos) (Guadalupe, 2010; Guadalupe e Vicente, 2012) e um questionário para descrever sociodemograficamente a amostra. Participantes: A amostra é constituída por 567 idosos (M = 75,53 anos), com predominância do sexo feminino (64,1%). A maioria é casada (53,8%) e detém a 4ª classe (51,3%). Os participantes, na sua maioria, têm filhos (87,8%) e não vivem sós (79,4%). Resultados: As redes são compostas em média por 8 elementos, dominadas por laços familiares (M = 76,90%). São redes coesas, com relações interpessoais duradouras, com pouca dispersão geográfica e elevada frequência de contactos. O apoio percebido nas redes é sobretudo emocional e informativo. Quanto à sua composição, 43,7% dos idosos têm uma rede exclusivamente familiar, 53,4% redes com família e outros campos relacionais e apenas 2,8% apresentam redes sem família. Os idosos com 76-85 anos, casados e com agregado familiar numeroso têm maior probabilidade de pertencer a redes exclusivamente familiares. Os idosos mais jovens e divorciados tendem a pertencer a redes mais diversificadas, enquanto as mulheres e os indivíduos solteiros e sem filhos têm maior probabilidade de não ter laços familiares nas suas redes, compensando a sua ausência com relações de amizade e de vizinhança. As redes exclusivamente familiares estão associadas a maior perceção de apoio emocional, material e instrumental, companhia social e reciprocidade de apoio. As redes com família e outras composições caraterizam-se por ter mais elementos e uma maior dispersão geográfica. As redes sem família são as mais reduzidas e são normalmente homogéneas para o género feminino e a nível etário, no grupo idoso. Conclusões: Fica patente o papel central das famílias nas redes e no apoio informal. Contudo, será essencial potenciar a diversificação e manutenção dos vínculos promovendo o acesso a novos contactos ao longo de todo o ciclo vital, de forma a garantir uma rede social pessoal diversificada e efetiva, em vínculos e recursos, que complemente as necessidades e favoreça o bem-estar da pessoa idosa. / Objectives: To analyze the sociodemographical and personal social networks characteristics of the elderly according to the composition of the networks centered on the families. Methodology: For characterizing the personal social networks we used the Instrumento de Análise da Rede Social Pessoal (IARSP-Idosos) (Guadalupe, 2010; Guadalupe e Vicente, 2012) and for sociodemographic characteristics we used a questionnaire. Participants: The sample consisted of 567 elderly (M = 75.53 years), mainly female (64.1%). The majority are married (53.8%) and have the 4th grade (51,3%). Overall the participants have offspring (87.8%) and do not live alone (79.4%). Results: On average, the networks have 8 elements, mostly relatives (M = 76.90%). The networks are cohesive, long-lasting, have a low geographical spread and we observed a high frequency of contacts. The networks provide mostly emotional (M = 2.64) and informative support (M = 2.37). Regarding its composition, 43.7% of the elderly have an exclusively family network, 53.4% have networks with family members and other relational fields and only 2.8% have no relatives in their networks. The elderly whose age is between 76-85 years, married and with a large household are more likely to belong to exclusively family networks. Younger and divorced elderly tend to belong to more diverse networks, as women and individuals unmarried and without offspring are more likely to do not have family bounds in their networks, with a higher proportion of friends and neighbors. Exclusively family networks are associated with greater perception of emotional, material and instrumental support, social company and reciprocal support. Networks with family and other fields are characterized by having more elements and a greater geographical spread. The social networks without family are smaller and are usually homogeneous for female gender and age, in the elderly group. Conclusions: The role of families in providing informational support is clear. However, it will be essential to enhance the diversification and maintain ties that promote access to new contacts throughout our entire life, to ensure a diversified social network that will be effective in bonds and resources that complement the needs and encourages the well-being of the elderly.