<p>This dissertation contributes to the rapidly growing empirical research area in the field of operations management. It contains two essays, tackling two different sets of operations management questions which are motivated by and built on field data sets from two very different industries --- air cargo logistics and retailing. </p><p>The first essay, based on the data set obtained from a world leading third-party logistics company, develops a novel and general Bayesian hierarchical learning framework for estimating customers' spillover learning, that is, customers' learning about the quality of a service (or product) from their previous experiences with similar yet not identical services. We then apply our model to the data set to study how customers' experiences from shipping on a particular route affect their future decisions about shipping not only on that route, but also on other routes serviced by the same logistics company. We find that customers indeed borrow experiences from similar but different services to update their quality beliefs that determine future purchase decisions. Also, service quality beliefs have a significant impact on their future purchasing decisions. Moreover, customers are risk averse; they are averse to not only experience variability but also belief uncertainty (i.e., customer's uncertainty about their beliefs). Finally, belief uncertainty affects customers' utilities more compared to experience variability. </p><p>The second essay is based on a data set obtained from a large Chinese supermarket chain, which contains sales as well as both wholesale and retail prices of un-packaged perishable vegetables. Recognizing the special characteristics of this particularly product category, we develop a structural estimation model in a discrete-continuous choice model framework. Building on this framework, we then study an optimization model for joint pricing and inventory management strategies of multiple products, which aims at improving the company's profit from direct sales and at the same time reducing food waste and thus improving social welfare.</p><p>Collectively, the studies in this dissertation provide useful modeling ideas, decision tools, insights, and guidance for firms to utilize vast sales and operations data to devise more effective business strategies.</p> / Dissertation

La thèse propose d'appréhender le concept d'équité en matière d'accès aux soins de santé selon de multiples aspects en adoptant une réflexion axée initialement sur les fondements normatifs des conceptions théoriques pour parvenir progressivement aux conceptions profanes. Pour alimenter cette réflexion progressive, une première partie est dédiée à la présentation des différents niveaux de débats qui s'articulent tout au long de ce cheminement. Une vue d'ensemble est dressée afin de mettre en exergue les complémentarités potentielles et l'apport interactif qui lient les différentes approches. La suite de la réflexion s'axe sur les conceptions profanes. Les parties 2 et 3 de la thèse apportent des éclairages à l'élicitation des conceptions profanes. A cette fin, nous avons eu recours à deux méthodologies empiriques de révélation spécifiques. (i) Dans la partie 2, l'expérience que nous proposons est destinée à éliciter les préférences sous « condition d'impartialité » auprès de sujets présentant des caractéristiques différentes : des sujets-étudiants d'une part, puis un groupe plus hétérogène comprenant des patients hospitalisés, des représentants d'usagers et des membres d'association d'autre part. Selon cette approche, nous avons testé certains principes normatifs de justice en les confrontant aux opinions exprimées par les sujets participant aux expériences. (ii) Dans la partie 3, nous avons eu recours à une méthode inductive de recueil d'opinion avec comme sujets un groupe de médecins traitants. La méthodologie adopte ainsi un angle différent puisque nous cherchons à faire émerger des principes de justice de manière inductive. En somme, les parties 2 et 3 de la thèse offrent deux approches empiriques complémentaires pour parvenir à une certaine connaissance des conceptions profanes de l'équité en santé. / The thesis proposes to understand the concept of equity in access to health care in multiple aspects by adopting a reflection initially focused on the normative foundations of theoretical concepts to achieve progressively to profane ones. To supply this progressive thinking, first part is dedicated to the presentation of different levels of discussions. An overview is drawn to highlight the potential complementarities and interactive contributions that link different approaches. Parts 2 and 3 of the thesis provide insight to express profane conceptions. To this end, we used two empirical methodologies of specific revelation. (i) In Part 2, the experience we purpose is designed to elicit preferences under «impartiality» in subjects with different characteristics: subjects - students on the one hand, and a more heterogeneous group including patients, user representatives and members of associations on the other. Under this approach, we tested some normative principles of justice by confronting the views expressed by the subjects participating in the experiments. (ii) In Part 3, we used an inductive method for collecting opinion as subjects with a group of doctors. Methodology takes a different angle focused on principles of justice emergence inductively. To sum up, Parts 2 and 3 of the thesis offer two complementary empirical approaches to bring some knowledge of profane conceptions in health equity.

The aim of this thesis is empirical verification of the fundamental theory of exchange rate determination in the case of the currency pair EUR/USD. The theoretical part is devoted to the issue of exchange rate theory, with emphasis on the importance of the currency pair EUR/USD, and major characteristics of the fundamental theory of exchange rate determination. Attention is also paid to methods of analysis of time series, which will be used in the analytical part. The analytical part is devoted to an empirical verification of the underlying theories. On the basis of these theories are developed econometric models, which are then tested using the methods of linear regression and cointegration. The results of the models and their relevance are discussed in conclusion.

In this paper we aim to improve existing empirical exchange rate models by accounting for uncertainty with respect to the underlying structural representation. Within a flexible Bayesian non-linear time series framework, our modeling approach assumes that different regimes are characterized by commonly used structural exchange rate models, with their evolution being driven by a Markov process. We assume a time-varying transition probability matrix with transition probabilities depending on a measure of the monetary policy stance of the central bank at the home and foreign country. We apply this model to a set of eight exchange rates against the US dollar. In a forecasting exercise, we show that model evidence varies over time and a model approach that takes this empirical evidence seriously yields improvements in accuracy of density forecasts for most currency pairs considered. / Series: Department of Economics Working Paper Series

Thesis advisor: Ronnie Sadka / In the first essay of this dissertation, I study the impact that hedge fund manager connections have on investment ideas. I find that hedge fund managers who previously worked at the same prior hedge fund invest more similarly, hold more overlapping portfolios, and trade and overweight the same stocks relative to managers who do not share an employment connection. Overall, these results support theoretical prediction that networked managers share ideas that leads to price discovery for commonly held stocks. The second essay analyzes the role of ETFs in mutual fund families and is joint work with Caitlin Dannhauser. We study mutual fund and ETF twins - index funds from the same family that follow the same benchmark. We find that mutual fund twins have lower overall tax burdens while ETF twins have higher long-term yields and unrealized capital gains, but are compensated with lower expense ratios. Fund families benefit because twin offerings generate higher flows than their non-twin peers. These results support previous research that mutual fund families use diversification and subsidization to benefit the overall family. In the third essay, I study the use of latent factors in explaining hedge fund returns. Using an alternative latent factor estimator, asymptotic principal components (APC), I find explains more of the common variation of hedge fund returns on average and does so with greater efficiency than that found in the literature. I also identify an increase in the common variation across hedge fund excess return in the time-series via the extracted latent factors. My results suggest an impetus for future researchers to employ APC factors when characterizing hedge fund performance. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Carroll School of Management. / Discipline: Finance.

This paper explores the fit of a stochastic volatility model, in which the Box-Cox transformation of the squared volatility follows an autoregressive Gaussian distribution, to the continuously compounded daily returns of the Australian stock index. Estimation was difficult, and over-fitting likely, because more variables are present than data. We developed a revised model that held a couple of these variables fixed and then, further, a model which reduced the number of variables significantly by grouping trading days. A Metropolis-Hastings algorithm was used to simulate the joint density and derive estimated volatilities. Though autocorrelations were higher with a smaller Box-Cox transformation parameter, the fit of the distribution was much better.

A crescente adoção do paradigma experimental na pesquisa em Engenharia de Software visa a obtenção de evidências experimentais sobre as tecnologias propostas para garantir sua correta avaliação e para a construção de um corpo de conhecimento sólido da disciplina. Uma das abordagens de pesquisa experimental é a revisão sistemática, um método rigoroso, planejado e auditável para a realização da coleta e análise crítica de dados experimentais disponíveis sobre um determinado tema de pesquisa. Apesar de produzir resultados confiáveis, a condução de uma revisão sistemática pode ser trabalhosa e muitas vezes demorada, principalmente quando existe um grande volume de estudos a serem considerados, selecionados e avaliados. Uma solução encontrada na literatura é a utilização de ferramentas de Mineração Visual de Textos (VTM) como a Projection Explorer (PEx) para apoiar a fase de seleção e análise de estudos primários no processo de revisão sistemática. Neste trabalho foi realizada uma reengenharia de software na ferramenta PEx com dois objetivos principais: apoiar, utilizando VTM, a fase de seleção e análise de estudos primários no processo de revisão sistemática e implementar novos requisitos não-funcionais relativos à melhoria da manutenibilidade e escalabilidade da ferramenta. Como resultado foi construída uma plataforma modular para a instanciação de ferramentas de visualização e, a partir da mesma, uma ferramenta de revisão sistemática apoiada por VTM. Os resultados de um estudo de caso executado com a ferramenta mostraram que a abordagem de aplicação de técnicas VTM usada nesse contexto é viável e promissora, melhorando tanto a performance quanto a efetividade da seleção / The increasing adoption of the experimental paradigm in Software Engineering research aims at obtaining experimental evidence of the proposed technologies to ensure their proper evaluation and to build a solid body of knowledge for the discipline. One approach of experimental research is the systematic review, a rigorous, auditable and planned method to carry out the collection and analysis of experimental data available on a particular research topic. Despite producing reliable results, conducting a systematic review can be a cumbersome and often lengthy process, especially when a large volume of studies is to be considered, selected and evaluated. One solution found in the literature is the use of Visual Text Mining (VTM) tools such as the Projection Explorer (PEx) to support the selection and analysis of primary studies in the systematic review process. In this work a software re-engineering was performed on PEx with two main goals: to support, using VTM, the stage of selection and analysis of primary studies in the systematic review process and to implement new non-functional requirements related to improving the maintainability and scalability of the tool. The results were the building of a modular platform for instantiating visualization tools and, from it, the instantiation of a systematic review tool supported by VTM. The results of a case study carried out with the tool showed that the VTM approach used in this context is feasible and promising, improving both performance and the effectiveness of selection

Neste trabalho analisam-se os modelos conceituais e operacionais de brand equity baseado no cliente apresentados na literatura acadêmica. Sendo essa a alternativa para explorar o tema: documentar os modelos de brand equity, bem como as diferenças conceituais e empíricas entre os modelos de brand equity, pela ótica do cliente. Neste contexto, surge o seguinte problema de pesquisa: Os modelos existentes na literatura (teórico-práticos) de brand equity, baseado no cliente, podem compor um modelo de mensuração aplicável à realidade brasileira? Para isso faz-se uma pesquisa descritiva com o intuito de apresentar e enumerar os modelos de brand equity baseados no cliente, constantes entre os autores em ciências sociais aplicadas. Os resultados dessa parte do trabalho são tabelas resumo da literatura, apresentadas em capítulo específico, bem como as interpretações provenientes dessas análises. Elabora-se, então, uma pesquisa empírica para verificar a relação existente entre as dimensões que compõem o brand equity baseado no cliente e o mix de marketing organizacional. É desenvolvido análise da literatura, análise de confiabilidade, regressões, e modelagem de equações estruturais. Nessa pesquisa empírica encontra-se as análises de confiabilidade (Alpha de Cronbach´s), onde verificou-se que as dimensões propostas inicialmente por Aaker (1998) e Keller (1993) têm alta confiabilidade de escala. O patrimônio total da marca e a percepção dos preços, propostos por Yoo, Donthu e Lee (2000) também têm alto poder de confiabilidade na escala em português. Na análise das regressões completa, tradicional, e confiável do brand equity, baseado no cliente, houve uma semelhança de resultados. Apesar de algumas diferenças nos números e valores de R2 e de erro, esses foram muito próximos deixando as três equações propostas com mesma significância e valor de predição. Esse valor de predição para as três equações de regressão são moderados/baixos, demonstrando uma predição da variável dependente em grau leve pelas variáveis independentes, propostas nos modelos de regressão. Seguidos das análises de ajustes, verossimilhança, e significância da modelagem de equações estruturais m.e.e. Os objetivos do trabalho, propostos inicialmente, foram alcançados de forma clara e apresentados melhor no decorrer deste trabalho. Essa pesquisa empírica foi replicada para o Brasil, utilizando-se como base o trabalho de Yoo, Donthu e Lee (2000), sendo uma investigação agora desenvolvida nacionalmente. Tendo como alvo da pesquisa o setor de sapatos esportivos de uma grande marca mundial Adidas. / In this paper examine the conceptual and operational models of based-client brand equity presented in the academic literature. This being the alternative to explore the theme: documenting models of brand equity, as well as differences between the conceptual and empirical models of brand equity, through the eyes of the customer. In this context, there arises the following research problem: The existing models in the literature (theoretical and practical) of based-client brand equity can make a measurement model applicable to the Brazilian reality? For this it is a descriptive research in order to present and list the models of basedclient brand equity, listed among the authors applied social sciences. The results of this study are part of the summary tables of literature, presented in separate chapter, as well as interpretations from these tests. It elaborates, then, empirical research to verify the relationship between the dimensions that comprise the client-based brand equity and organizational marketing mix. It is developed literature analysis, reliability analysis, regression, and structural equation modeling. In this empirical research is the analysis of reliability (Cronbach\'s Alpha), where it was found that the dimensions initially proposed by Aaker (1998) and Keller (1993) have high reliability scale. The total equity of the brand and the perception of prices, proposed by Yoo, Donthu and Lee (2000) also have high reliability in the power of scale in Portuguese. In the analysis of complete regressions, traditional and trusted brand equity, based on the client, there was a similarity of results. Despite some differences in the numbers and values of R2 and error, these were very close to leaving the three equations with the same significance and value prediction. This predictive value for the three regression equations are moderate / low, showing a prediction of the dependent variable in mild by the independent variables proposed in the regression models. Followed by analysis of settings, likelihood and significance of structural equation modeling s.e.m. The objectives of the work originally proposed, were reached in a clear and better presented in this all paper. This empirical research has been replicated in Brazil, using as basis the work of Yoo, Donthu and Lee (2000), an investigation now being developed nationally. Targeting the research sector of athletic shoes of a great global brand - Adidas.

Esse trabalho tem como objetivo verificar se o sistema bancário brasileiro protege indivíduos contra os choques transitivos de renda. Por meio de experimentos e avaliação empírica, em pequenas regiões, a literatura tenta explicar como arranjos informais podem contornar os problemas de crédito causados por falhas informacionais e de comprometimento limitado. No entanto, falha em avaliar choques que afetam uma região geográfica ampla já que esses são comportados apenas por bancos. Através de um modelo de dois estágios com variação de renda instrumentalizada por variáveis climáticas, analisamos se existe um efeito significante entre os choques e as contas de crédito das instituições formais. Verificamos que os agentes usam poupança como meio principal de suavizar seu risco intertemporal. As contas de crédito, entretanto possuem um efeito distinto em municípios com mais desenvolvimento financeiro do que aqueles com menos. Isso indica que possuímos uma restrição de crédito para parte da população, deixando-a exposta ao seu risco. / This work aims to verify whether the Brazilian banking system protects individuals against transitive income shocks. Through experiments and empirical evaluation in small regions, literature tries to explain how informal arrangements can overcome credit problems caused by informational failures and limited commitment. But they fail to evaluate shocks that affect a broad geographic region that can only be dealt with banks. Through a two-stage model with varying income instrumentalized by climatic variables, we analyze whether there is a significant effect between shocks and credit accounts of formal institutions. We verify that agents use savings as the primary means of smoothing their intertemporal risk. The credit accounts however have a distinct effect in counties with more financial development than the ones with the least. This indicates that we have a credit crunch for a portion of the population, leaving it exposed to their risk.

Software startups face a very demanding market: they must deliver high innovative solutions in the shortest possible period of time. Resources are limited and time to reach market is short. Then, it is extremely important to gather the right requirements and that they are precise. Nevertheless, software requirements are usually not clear and startups struggle to identify what they should build. This context affects how requirements engineering activities are performed in these organizations. This work seeks to characterize the state-of-practice of requirements engineering in software startups. Using an iterative approach, seventeen interviews were conducted during three stages with founders and/or managers of different Brazilian software startups operating in different market sectors and with different maturity levels. Data was analyzed using grounded theory techniques such open and axial coding through continuous comparison. As a result, a conceptual model of requirements engineering state-of-practice in software startups was developed consisting of its context influences (founders, software development manager, developers, business model, market and ecosystem) and activities description (product team; elicitation; analysis, validation and prioritization; product validation and documentation). Software development and startup development techniques are also presented and their use in the startup context is analyzed. Finally, using a bad smell analogy borrowed from software development literature, some bad practices and behaviors identified in software startups are presented and solutions to avoid them proposed. / Startups de software enfrentam um mercado muito exigente: elas devem entregar soluções altamente inovativas no menor período de tempo possível. Recursos são limitados e tempo para alcançar o mercado é pequeno. Então, é extremamente importante coletar os requisitos certos e que eles sejam precisos. Entretanto, os requisitos de software geralmente não são claros e as startups fazem um grande esforço para identificar quais serão implementados. Esse contexto afeta como as atividades de engenharia de requisitos são executadas nessas organizações. Este trabalho procura compreender o estado-da-prática da engenharia de requisitos em startups de software. Usando uma abordagem iterativa, dezessete entrevistas foram realizados em três diferentes estágios com fundadores e/ou gestores de diferentes startups de software brasileiras operando em diferentes setores e com diferentes estágios de maturidade. Os dados foram analisados usando técnicas de teoria fundamentada como codificação aberta e axial através da comparação contínua. Como resultado, um modelo conceitual do estado-da-prática da engenharia de requisitos em startups de software foi desenvolvido consistindo da suas influências do contexto (fundadores, gerente de desenvolvimento de software, desenvolvedores, modelo de negócio, mercado e ecossistema) e descrição das atividades (time de produto; levantamento; análise, validação e priorização; e documentação). Técnicas oriundas de metodologias de desenvolvimento de software e desenvolvimento de startups também são apresentadas e seu uso em no contexto de startups é analisado. Finalmente, a partir de uma analogia de maus cheiros presente na literatura de desenvolvimento de software, algumas más práticas e maus comportamentos identificados em startups de software são apresentados e algumas sugestões de solução são propostas.