Optimal IV estimation of systems with stochastic regressors and var disturbances with applications to dynamic systems

This paper considers the general problem of Feasible Generalized Least Squares Instrumental Variables (FG LS IV) estimation using optimal instruments. First we summarize the sufficient conditions for the FG LS IV estimator to be asymptotic ally equivalent to an optimal G LS IV estimator. Then we specialize to stationary dynamic systems with stationary VAR errors, and use the sufficient conditions to derive new moment conditions for these models. These moment conditions produce useful IVs from the lagged endogenous variables, despite the correlation between errors and endogenous variables. This use of the information contained in the lagged endogenous variables expands the class of IV estimators under consideration and there by potentially improves both asymptotic and small-sample efficiency of the optimal IV estimator in the class. Some Monte Carlo experiments compare the new methods with those of Hatanaka [1976]. For the DG P used in the Monte Carlo experiments, asymptotic efficiency is strictly improved by the new IVs, and experimental small-sample efficiency is improved as well.

A study on time-varying quantile and its applications

This Thesis is the result of my Master Degree studies at the Graduate School of Economics, Getúlio Vargas Foundation, from January 2004 to August 2006. am indebted to my Thesis Advisor, Professor Luiz Renato Lima, who introduced me to the Econometrics' world. In this Thesis, we study time-varying quantile process and we develop two applications, which are presented here as Part and Part II. Each of these parts was transformed in paper. Both papers were submitted. Part shows that asymmetric persistence induces ARCH effects, but the LMARCH test has power against it. On the other hand, the test for asymmetric dynamics proposed by Koenker and Xiao (2004) has correct size under the presence of ARCH errors. These results suggest that the LM-ARCH and the Koenker-Xiao tests may be used in applied research as complementary tools. In the Part II, we compare four different Value-at-Risk (VaR) methodologies through Monte Cario experiments. Our results indicate that the method based on quantile regression with ARCH effect dominates other methods that require distributional assumption. In particular, we show that the non-robust method ologies have higher probability to predict VaRs with too many violations. We illustrate our findings with an empirical exercise in which we estimate VaR for returns of São Paulo stock exchange index, IBOVESPA, during periods of market turmoil. Our results indicate that the robust method based on quantile regression presents the least number of violations.

Essays in corporate risk management

This research investigates the factors that lead Latin American non-financial firms to manage risks using derivatives. The main focus is on currency risk management. With this purpose, this thesis is divided into an introduction and two main chapters, which have been written as stand-alone papers. The first paper describes the results of a survey on derivatives usage and risk management responded by the CFOs of 74 Brazilian non-financial firms listed at the São Paulo Stock Exchange (BOVESPA), and the main evidence found is: i) larger firms are more likely to use financial derivatives; ii) foreign exchange risk is the most managed with derivatives; iii) Brazilian managers are more concerned with legal and institutional aspects in using derivatives, such as the taxation and accounting treatment of these instruments, than with issues related to implementing and maintaining a risk management program using derivatives. The second paper studies the determinants of risk management with derivatives in four Latin American countries (Argentina, Brazil, Chile and Mexico). I investigate not only the decision of whether to use financial derivatives or not, but also the magnitude of risk management, measured by the notional value of outstanding derivatives contracts. This is the first study, to the best of my knowledge, to use derivatives holdings information in emerging markets. The use of a multi-country setting allows the analysis of institutional and economic factors, such as foreign currency indebtedness, the high volatility of exchange rates, the instability of political and institutional framework and the development of financial markets, which are issues of second-order importance in developed markets. The main contribution of the second paper is on the understanding of the relationship among currency derivatives usage, foreign debt and the sensitivity of operational earnings to currency fluctuations in Latin American countries. Unlikely previous findings for US firms, my evidence shows that derivatives held by Latin American firms are capable of producing cash flows comparable to financial expenses and investments, showing that derivatives are key instruments in their risk management strategies. It is also the first work to show strong and robust evidence that firms that benefit from local currency devaluation (e.g. exporters) have a natural currency hedge for foreign debt that allows them to bear higher levels of debt in foreign currency. This implies that firms under this revenue-cost structure require lower levels of hedging with derivatives. The findings also provide evidence that large firms are more likely to use derivatives, but the magnitude of derivatives holdings seems to be unrelated to the size of the firm, consistent with findings for US firms.

Essays on corporate restructuring

Esta tese tem por objetivo examinar as características do processo de decisão em que credores optam pela recuperação judicial ou liquidação da empresa em dificuldade financeira. O trabalho está dividido em quatro capítulos. No segundo capítulo, apresenta-se, de forma sistematizada, referencial teórico e evidências empíricas para apontar resultados importantes sobre estudos desenvolvidos nas áreas de recuperação de empresas e falência. O capítulo também apresenta três estudos de caso com o propósito de mostrar a complexidade de cada caso no que diz respeito à concentração de recursos, conflito de interesse entre as classes de credores e a decisão final sobre a aprovação ou rejeição do plano de recuperação judicial. No terceiro capítulo, analisam-se os determinantes do atraso pertinente à votação do plano de recuperação judicial. O trabalho propõe um estudo empírico dos atrasos entre 2005 e 2014. Os resultados sugerem que: (i) maior concentração da dívida entre as classes de credores possui relação com atrasos menores; (ii) maior quantidade de bancos para votar o plano de recuperação judicial possui relação com maiores atrasos; (iii) o atraso médio na votação diminui quando apenas uma classe de credores participa da votação do plano; (iv) credores trabalhistas e com garantia real atrasam a votação quando o valor dos ativos para garantir a dívida em caso de liquidação é maior; (v) o atraso médio na votação é maior em casos de pior desempenho do setor de atuação do devedor, sendo solicitado pelas classes quirografária e com garantia real; e (vi) a proposta de venda de ativos é o principal tópico discutido nas reuniões de votação do plano nos casos em que o atraso na votação é maior. Por fim, no quarto capítulo, apresenta-se evidência sobre a votação dos credores e a probabilidade de aprovação do plano de recuperação judicial. Os resultados sugerem que: (i) credores trabalhistas estão propensos a aprovar o plano de recuperação mesmo quando o plano é rejeitado pelas demais classes; (ii) planos com propostas de pagamento mais heterogêneas para as três classes de credores possuem menor chance de serem aceitos; (iii) a chance de aprovação do plano diminui nos casos em que mais credores quirografários participam da recuperação; e (iv) planos com proposta de venda de ativos possuem maior chance de serem aprovados. Finalmente, maior concentração da dívida na classe com garantia real diminui a chance de aprovação do plano, e o contrário ocorre na classe quirografária.