Essays in Personal Transportation Demand and Consumer Finance

This dissertation is composed of three essays covering two areas of interest. The first topic is personal transportation demand with a focus on price and fuel efficiency elasticities of mileage demand, challenging assumptions common in the rebound effect literature. The second topic is consumer finance with a focus on small loans. The first chapter creates separate variables for fuel prices during periods of increasing and decreasing prices as well as an observed fuel economy measure to empirically test the equivalence of these elasticities. Using a panel from Germany from 1997 to 2009 I find a fuel economy elasticity of mileage of 53.3%, which is significantly different from the gas price elasticity of mileage during periods of decreasing gas prices, 4.8%. I reject the null hypothesis or price symmetry, with the elasticity of mileage during period of increasing gas prices ranging from 26.2% and 28.9%. The second chapter explores the potential for the rebound effect to vary with income. Panel data from U.S. households from 1997 to 2003 is used to estimate the rebound effect in a median regression. The estimated rebound effect independent of income ranges from 17.8% to 23.6%. An interaction of income and fuel economy is negative and significant, indicating that the rebound effect may be much higher for low income individuals and decreases with income; the rebound effect for low income households ranged from 80.3% to 105.0%, indicating that such households may increase gasoline consumption given an improvement in fuel economy. The final chapter documents the costs of credit instruments found in major mail order catalogs throughout the 20th century. This study constructs a new dataset and finds that the cost of credit increased and became stickier as mail order retailers switched from an installment-style closed-end loan to a revolving-style credit card. This study argues that revolving credit's ability to decrease salience of credit costs in the price of goods is the best explanation for rate stickiness in the mail order industry as well as for the preference of revolving credit among retailers.

On the Social Aspects of Unemployment: The Case of Life Satisfaction

Unemployment is related to economic, political and social aspects. One of the least analysed social aspects is the relationship between unemployment and the (individual) perceived levels of well-being, such as life satisfaction or happiness. This chapter complements previous work on the subject, using a panel-data econometrics methodology to analyze the relationship between unemployment and life satisfaction in a wide range of countries worldwide. The results confirm that unemployment has a negative effect, statistically significant, on life satisfaction, either for men or for women.

A indústria hoteleira do Algarve: uma análise de dados em painel da estrutura de capital

Dissertação de Mestrado, Finanças Empresariais, Faculdade de Economia, Universidade do Algarve, 2015

Factores determinantes das exportações portuguesas para Espanha : uma análise ao nível da empresa

Este estudo analisa a evolução das exportações portuguesas para Espanha e os seus factores determinantes no período 2004-2008, tendo por base uma amostra das 97 maiores empresas exportadoras para Espanha. O estudo utiliza vários indicadores económico-financeiros para caracterizar estas empresas e é feita a comparação entre as 5 maiores empresas e 5 pequenas e médias empresas (PMEs) da amostra. A análise evidencia a concentração geográfica destas empresas nos distritos de Porto e Aveiro e o melhor desempenho das grandes empresas em termos de produtividade, rendibilidade dos capitais próprios e salário médio quando comparadas com as PMEs. Quanto ao estudo econométrico, que utiliza dados em painel, consideraram-se como variáveis explicativas teoricamente relevantes, o valor acrescentado bruto, os resultados líquidos, os capitais próprios, a dimensão da empresa, a remuneração e as despesas em investigação e desenvolvimento (I&D). Os resultados do modelo estimado confirmam a influência positiva destas variáveis sobre a variação das exportações, embora as despesas em I&D e as remunerações se tenham revelado estatisticamente não significativas.

Corporate governance : value creation and performance in credit unions

In this study, we examine the relationship between good corporate governance practices and the creation of value/performance of credit unions from 2010 to 2012. The objective was to create and validate a corporate governance index for credit unions, and to then analyse the relationship between good governance practices and the creation of value/performance. The problem question is: do good corporate governance practices provide value creation for credit unions? The research started by creating indices from factor analysis to identify latent dependent variables related to value creation and performance; next indices were created from the principal component analysis for the creation of independent latent variables related to corporate governance. Finally, based on panel data from regression models, the influence of the variables and indices related to corporate governance on the indices of value creation and performance was verified. Based on the research, it became evident that the Corporate Governance Index (IGC) is mainly impacted by Executive Management, with 40.31% of the IGC value, followed by the Representation and Participation dimension, with 34.07% of the IGC value. The contribution for academics was the creation of the Corporate Governance Index (IGC) applied for credit unions. As for the contribution to the system of credit unions, the highlight was the effectiveness of the mechanisms for economic-financial and asset management adopted by BACEN, credit unions and OCEMG.

Determinantes del spread financiero del sector cooperativo de ahorro y crédito ecuatoriano

Esta investigación analiza los determinantes del spread financiero del sector cooperativo de ahorro y crédito ecuatoriano. La base teórica corresponde al modelo expuesto por Ho y Saunders (1981). Se construyeron variables micro y macroeconómicas para recoger los efectos que estas tienen sobre el margen de intermediación financiera. Se empleó un panel de datos mensuales para el periodo 2007-2014. Las estimaciones fueron realizadas mediante la metodología de errores estándar corregidos para datos de panel. Los resultados explican que el spread financiero del sector cooperativo depende particularmente de los niveles de morosidad, la eficiencia en sus gastos operacionales y el grado de endeudamiento público externo de la economía. Además, la concentración de mercado, los niveles de liquidez y la incertidumbre en los mercados internacionales inciden levemente en la determinación del spread.

Essays on employment / education, investment in education and student achievement

Méthodologie: Modèle de régression quantile de variable instrumentale pour données de Panel utilisant la fonction de production partielle

Essays on firm behaviour in the euro area

This thesis examines firms' real decisions using a large panel of unquoted euro area firms over the period 2003-2011. To this end, this thesis is composed of five chapters in which three are the main empirical chapters. They assess the dimensions of firm behaviour across different specifications. Each of these chapters provide a detailed discussion on the contribution, theoretical and empirical background as well as the panel data techniques which are implemented. Chapter 1 describes the introduction and outline of the thesis. Chapter 2 presents an empirical analysis on the link between financial pressure and firms' employment level. In this set-up, it is explored the strength of financial pressure during the financial crisis. It is also tested whether this effect has a different impact for financially constrained and unconstrained firms in the periphery and non-periphery regions. The results of this chapter denote that financial pressure exerts a negative impact on firms' employment decisions and that this effect is stronger during the crisis for financially constrained firms in the periphery. Chapter 3 analyses the cash policies of private and public firms. Controlling for firm size and other standard variables in the literature of cash holdings, empirical findings suggest that private firms hold higher cash reserves than their public counterparts indicating a greater precautionary demand for cash by the former. The relative difference between these two type of firms decreases (increases) the higher (lower) is the the level of financial pressure. The findings are robust to various model specifications and over different sub-samples. Overall, this chapter shows the relevance of firms' size. Taken together, the findings of Chapter 3 are in line with the early literature on cash holdings and contradict the recent studies, which find that the precautionary motive to hold cash is less pronounced for private firms than for public ones. Chapter 4 undertakes an investigation on the relation between firms' stocks of inventories and trade credit (i.e. extended and taken) whilst controlling for the firms' size, the characteristics of the goods transacted, the recent financial crisis and the development of the banking system. The main findings provide evidence of a trade-off between trade credit extended and firms' stock of inventories. In other words, firms' prefer to extend credit in the form of stocks to their financially constrained customers to avoid holdings costly inventories and to increase their sales levels. The provision of trade credit by the firms also depends on the characteristics of the goods transacted. This impact is stronger during the crisis. Larger and liquid banking systems reduce the trade-off between the volume of stocks of inventories and the amount sold on credit. Trade credit taken is not affected by firms' stock of inventories. Chapter 5 presents the conclusions of the thesis. It provides the main contributions, implications and future research of each empirical chapter.

BM: Tributación y concentración en el sistema financiero Colombiano 1989 - 2003

El presente documento analiza los determinantes del margen de intermediación para el sistema financiero colombiano entre 1989 y 2003. Bajo una estimación dinámica de los efectos generados por variables específicas de actividad, impuestos y estructura de mercado, se presenta un seguimiento del margen de intermediación financiero, para un período que presenta elementos de liberalización y crisis.

Estudio de empresas de sectores hegemónicos en Colombia para los años 2013 y 2014

Este documento evidencia las posiciones hegemónicas que han llegado a ocupar las empresas más poderosas del país, basándose en el estudio de datos cuantitativos del conteo de las cien empresas con mejores ventas para los años 2013 y 2014, según la revista Gerente. Se usan cinco variables: ventas totales, activos, pasivos, patrimonio y utilidades netas. En la primera sección, se hace una revisión bibliográfica que conecta el origen de la hegemonía en un panorama económico con la influencia del neoliberalismo y la globalización en el actual tejido industrial colombiano. Posteriormente, se realiza una explicación sobre la metodología aplicada para el estudio de la base de datos; la cual es seguida por una exposición de los resultados obtenidos a partir de herramientas estadísticas como el análisis de correlación lineal, quintiles y variaciones porcentuales. Finalmente, se aborda el Programa de Transformación Productiva, esto con el objetivo de mostrar los puntos focales que necesitan especial atención para lograr catalizar el desarrollo económico de Colombia.

Civil conflict and voting behavior : evidence from Colombia

¿Cuáles son los efectos de la guerra sobre el comportamiento político? Colombia es un caso interesante en el que el conflicto y las elecciones coexisten y los grupos armados ilegales intencionalmente afectan los resultados electorales. Sin embargo, los grupos usan diferentes estrategias para alterar estos resultados. Este artículo argumenta que los efectos diferenciales de la violencia sobre los resultados electorales son el resultado de estrategias deliberadas de los grupos ilegales, que a su turno, son consecuencia de las condiciones militares que difieren entre ellos. Usando datos panel de las elecciones al Senado de 1994 a 2006 y una aproximación por variables instrumentales para resolver posibles problemas de endogenidad, este artículo muestra que la violencia guerrillera disminuye la participación electoral, mientras que la violencia paramilitar no tiene ningún efecto sobre la participación pero reduce la competencia electoral y beneficia a nuevos partidos no-tradicionales. Esto es consistente con la hipótesis de que la estrategia de la guerrilla es sabotear las elecciones, mientras que los paramiltares establecen alianzas con ciertos candidatos.

Modelling spillover effects in spatial stochastic frontier analysis

In the last two decades, authors have begun to expand classical stochastic frontier (SF) models in order to include also some spatial components. Indeed, firms tend to concentrate in clusters, taking advantage of positive agglomeration externalities due to cooperation, shared ideas and emulation, resulting in increased productivity levels. Until now scholars have introduced spatial dependence into SF models following two different paths: evaluating global and local spatial spillover effects related to the frontier or considering spatial cross-sectional correlation in the inefficiency and/or in the error term. In this thesis, we extend the current literature on spatial SF models introducing two novel specifications for panel data. First, besides considering productivity and input spillovers, we introduce the possibility to evaluate the specific spatial effects arising from each inefficiency determinant through their spatial lags aiming to capture also knowledge spillovers. Second, we develop a very comprehensive spatial SF model that includes both frontier and error-based spillovers in order to consider four different sources of spatial dependence (i.e. productivity and input spillovers related to the frontier function and behavioural and environmental correlation associated with the two error terms). Finally, we test the finite sample properties of the two proposed spatial SF models through simulations, and we provide two empirical applications to the Italian accommodation and agricultural sectors. From a practical perspective, policymakers, based on results from these models, can rely on precise, detailed and distinct insights on the spillover effects affecting the productive performance of neighbouring spatial units obtaining interesting and relevant suggestions for policy decisions.

Network analysis and machine learning assist drug repurposing and safety assessment in neurological diseases

In recent decades, two prominent trends have influenced the data modeling field, namely network analysis and machine learning. This thesis explores the practical applications of these techniques within the domain of drug research, unveiling their multifaceted potential for advancing our comprehension of complex biological systems. The research undertaken during this PhD program is situated at the intersection of network theory, computational methods, and drug research. Across six projects presented herein, there is a gradual increase in model complexity. These projects traverse a diverse range of topics, with a specific emphasis on drug repurposing and safety in the context of neurological diseases. The aim of these projects is to leverage existing biomedical knowledge to develop innovative approaches that bolster drug research. The investigations have produced practical solutions, not only providing insights into the intricacies of biological systems, but also allowing the creation of valuable tools for their analysis. In short, the achievements are: • A novel computational algorithm to identify adverse events specific to fixed-dose drug combinations. • A web application that tracks the clinical drug research response to SARS-CoV-2. • A Python package for differential gene expression analysis and the identification of key regulatory "switch genes". • The identification of pivotal events causing drug-induced impulse control disorders linked to specific medications. • An automated pipeline for discovering potential drug repurposing opportunities. • The creation of a comprehensive knowledge graph and development of a graph machine learning model for predictions. Collectively, these projects illustrate diverse applications of data science and network-based methodologies, highlighting the profound impact they can have in supporting drug research activities.

Modeling usage of medical care services: the medical expenditure panel survey data, 1996-2000

We explore the determinants of usage of six different types of health care services, using the Medical Expenditure Panel Survey data, years 1996-2000. We apply a number of models for univariate count data, including semiparametric, semi-nonparametric and finite mixture models. We find that the complexity of the model that is required to fit the data well depends upon the way in which the data is pooled across sexes and over time, and upon the characteristics of the usage measure. Pooling across time and sexes is almost always favored, but when more heterogeneous data is pooled it is often the case that a more complex statistical model is required.

Statistical analysis of survey-based event history data with application to modeling of unemployment duration

Longitudinal surveys are increasingly used to collect event history data on person-specific processes such as transitions between labour market states. Surveybased event history data pose a number of challenges for statistical analysis. These challenges include survey errors due to sampling, non-response, attrition and measurement. This study deals with non-response, attrition and measurement errors in event history data and the bias caused by them in event history analysis. The study also discusses some choices faced by a researcher using longitudinal survey data for event history analysis and demonstrates their effects. These choices include, whether a design-based or a model-based approach is taken, which subset of data to use and, if a design-based approach is taken, which weights to use. The study takes advantage of the possibility to use combined longitudinal survey register data. The Finnish subset of European Community Household Panel (FI ECHP) survey for waves 1–5 were linked at person-level with longitudinal register data. Unemployment spells were used as study variables of interest. Lastly, a simulation study was conducted in order to assess the statistical properties of the Inverse Probability of Censoring Weighting (IPCW) method in a survey data context. The study shows how combined longitudinal survey register data can be used to analyse and compare the non-response and attrition processes, test the missingness mechanism type and estimate the size of bias due to non-response and attrition. In our empirical analysis, initial non-response turned out to be a more important source of bias than attrition. Reported unemployment spells were subject to seam effects, omissions, and, to a lesser extent, overreporting. The use of proxy interviews tended to cause spell omissions. An often-ignored phenomenon classification error in reported spell outcomes, was also found in the data. Neither the Missing At Random (MAR) assumption about non-response and attrition mechanisms, nor the classical assumptions about measurement errors, turned out to be valid. Both measurement errors in spell durations and spell outcomes were found to cause bias in estimates from event history models. Low measurement accuracy affected the estimates of baseline hazard most. The design-based estimates based on data from respondents to all waves of interest and weighted by the last wave weights displayed the largest bias. Using all the available data, including the spells by attriters until the time of attrition, helped to reduce attrition bias. Lastly, the simulation study showed that the IPCW correction to design weights reduces bias due to dependent censoring in design-based Kaplan-Meier and Cox proportional hazard model estimators. The study discusses implications of the results for survey organisations collecting event history data, researchers using surveys for event history analysis, and researchers who develop methods to correct for non-sampling biases in event history data.