The risk premium on brazilian government debt, 1996-2002

The goal of this paper is to identify the determinants of the risk premium on Brazilian government debt. As the risk premium is a component of the interest rate set by the Brazilian central bank, its reduction would make it possible for the central bank to cut interest rates to levels compatible with a higher economic growth environment. The empirical evidence presented in this paper does not reject the hypotheses that fiscal solvency and the size of the public debt affect the risk premium as measured by the spread over treasury bills of the Brazilian C-bond.

Optimal auctions in a general model of identical goods

In this paper I study optimal auctions of identical goods. There is synergy in the number of goods and independent bidder’s signals.

Are one-sided S,s rules useful proxies for optimal pricing rules?

This article is motivated by the prominence of one-sided S,s rules in the literature and by the unrealistic strict conditions necessary for their optimality. It aims to assess whether one-sided pricing rules could be an adequate individual rule for macroeconomic models, despite its suboptimality. It aims to answer two questions. First, since agents are not fully rational, is it plausible that they use such a non-optimal rule? Second, even if the agents adopt optimal rules, is the economist committing a serious mistake by assuming that agents use one-sided Ss rules? Using parameters based on real economy data, we found that since the additional cost involved in adopting the simpler rule is relatively small, it is plausible that one-sided rules are used in practice. We also found that suboptimal one-sided rules and optimal two-sided rules are in practice similar, since one of the bounds is not reached very often. We concluded that the macroeconomic effects when one-sided rules are suboptimal are similar to the results obtained under two-sided optimal rules, when they are close to each other. However, this is true only when one-sided rules are used in the context where they are not optimal.

Optimal auction with a general distribution: virtual valuation without densities

We characterize the optimal auction in an independent private values framework for a completely general distribution of valuations. We do this introducing a new concept: the generalized virtual valuation. To show the wider applicability of this concept we present two examples showing how to extend the classical models of Mussa and Rosen and Baron and Myerson for arbitrary distributions

Private or public? a taxonomy of optimal ownership and management regimes

We develop a theory of public versus private ownership based on value diversion by managers. Government is assumed to face stronger institutional constraints than has been assumed in previous literature. The model which emerges from these assumptions is fexible and has wide application. We provide amapping between the qualitative characteristics of an asset, its main use - including public goods characteristics, and spillovers toother assets values - and the optimal ownership and management regime. The model is applied to single and multiple related assets. We address questions such as; when is it optimal to have one of a pair ofr elated assets public and the other private; when is joint management desirable; and when should a public asset be managed by the owner of a related private asset? We show that while private ownership can be judged optimal in some cases solely on the basis of qualitative information, the optimality of any other ownership and management regimes relies on quantitative analysis. Our results reveal the situations in which policy makers will have difficulty in determining the opimal regime.

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.

Endogenous debt constraints in collateralized economies with default penalties

In infinite horizon financial markets economies, competitive equilibria fail to exist if one does not impose restrictions on agents' trades that rule out Ponzi schemes. When there is limited commitment and collateral repossession is the unique default punishment, Araujo, Páscoa and Torres-Martínez (2002) proved that Ponzi schemes are ruled out without imposing any exogenous/endogenous debt constraints on agents' trades. Recently Páscoa and Seghir (2009) have shown that this positive result is not robust to the presence of additional default punishments. They provide several examples showing that, in the absence of debt constraints, harsh default penalties may induce agents to run Ponzi schemes that jeopardize equilibrium existence. The objective of this paper is to close a theoretical gap in the literature by identifying endogenous borrowing constraints that rule out Ponzi schemes and ensure existence of equilibria in a model with limited commitment and (possible) default. We appropriately modify the definition of finitely effective debt constraints, introduced by Levine and Zame (1996) (see also Levine and Zame (2002)), to encompass models with limited commitment, default penalties and collateral. Along this line, we introduce in the setting of Araujo, Páscoa and Torres-Martínez (2002), Kubler and Schmedders (2003) and Páscoa and Seghir (2009) the concept of actions with finite equivalent payoffs. We show that, independently of the level of default penalties, restricting plans to have finite equivalent payoffs rules out Ponzi schemes and guarantees the existence of an equilibrium that is compatible with the minimal ability to borrow and lend that we expect in our model. An interesting feature of our debt constraints is that they give rise to budget sets that coincide with the standard budget sets of economies having a collateral structure but no penalties (as defined in Araujo, Páscoa and Torres-Martínez (2002)). This illustrates the hidden relation between finitely effective debt constraints and collateral requirements.

Unemployment insurance an analysis of optimal mechanisms under aggregate shocks

The purpose of this work is to provide a brief overview of the literature on the optimal design of unemployment insurance systems by analyzing some of the most influential articles published over the last three decades on the subject and extend the main results to a multiple aggregate shocks environment. The properties of optimal contracts are discussed in light of the key assumptions commonly made in theoretical publications on the area. Moreover, the implications of relaxing each of these hypothesis is reckoned as well. The analysis of models of only one unemployment spell starts from the seminal work of Shavell and Weiss (1979). In a simple and common setting, unemployment benefits policies, wage taxes and search effort assignments are covered. Further, the idea that the UI distortion of the relative price of leisure and consumption is the only explanation for the marginal incentives to search for a job is discussed, putting into question the reduction in labor supply caused by social insurance, usually interpreted as solely an evidence of a dynamic moral hazard caused by a substitution effect. In addition, the paper presents one characterization of optimal unemployment insurance contracts in environments in which workers experience multiple unemployment spells. Finally, an extension to multiple aggregate shocks environment is considered. The paper ends with a numerical analysis of the implications of i.i.d. shocks to the optimal unemployment insurance mechanism.

Public debt and the limits of fiscal policy to increase economic growth

Research that seeks to estimate the effects of fiscal policies on economic growth has ignored the role of public debt in this relationship. This study proposes a theoretical model of endogenous growth, which demonstrates that the level of the public debt-to-gross domestic product (GDP) ratio should negatively impact the effect of fiscal policy on growth. This occurs because government indebtedness extracts part of the savings of the young to pay interest on the debts of the older generation, who are no longer saving. Therefore, the payment of debt interest assumes an allocation exchange role between generations that is similar to a pay-as-you-go pension system, which results in changes in the savings rate of the economy. The major conclusions of the theoretical model were tested using an econometric model to provide evidence for the validity of this conclusion. Our empirical analysis controls for timeinvariant, country-specific heterogeneity in the growth rates. We also address endogeneity issues and allow for heterogeneity across countries in the model parameters and for cross-sectional dependence.

The role of bond covenants and short-term debt: evidence from Brazil

Esta dissertação tem como objetivo analisar a relação entre covenants e alavancagem financeira no curto e longo prazo com oportunidades de crescimento. A partir de uma amostra de 159 debêntures, encontramos evidência de que: 1) Covenants e dívida de curto-prazo podem ser considerados substitutos na atenuação do conflito de agência, uma vez que apresentaram relação negativa e significante e; 2) A relação negativa existente entre dívida de curto prazo e oportunidades de crescimento pode ser reduzida através da utilização de covenants.

Optimal regulation of oil fields under asymmetric information

Neste trabalho é analisada a relação entre um regulador e uma empresa petrolífera. Há várias incertezas inerentes à essa relação e o trabalho se concentra nos efeitos da assimetria de informação. Fazemos a caracterização da regulação ótima sob informação assimétrica, quando o regulador deve desenhar um mecanismo que induz a firma a revelar corretamente sua informação privada. No caso em que a rma não pode se comprometer a não romper o acordo, mostramos que o regulador pode não implementar o resultado ótimo que é obtido sob informação completa. Nesse caso, o regulador não consegue compartilhar os riscos com a firma de forma ótima. Por fim, é apresentado um exemplo, em que mostramos que a condição de Spence-Mirrlees (SMC) pode não valer. Esse resultado aparece de forma natural no modelo.

A roughly smooth optimal consumption path: smoothing the rough annuity puzzle

A inconsistência entre a teoria e o comportamento empírico dos agentes no que tange ao mercado privado de pensões tem se mostrado um dos mais resistentes puzzles presentes na literatura econômica. Em modelos de otimização intertemporal de consumo e poupança sob incerteza em relação ao tempo de vida dos agentes, anuidades são ativos dominantes, anulando ou restringindo fortemente a demanda por ativos cujos retornos não estão relacionados à probabilidade de sobrevivência. Na prática, entretanto, consumidores são extremamente céticos em relação às anuidades. Em oposição ao seguro contra longevidade oferecido pelas anuidades, direitos sobre esses ativos - essencialmente ilíquidos - cessam no caso de morte do titular. Nesse sentido, choques não seguráveis de liquidez e a presença de bequest motives foram consideravelmente explorados como possíveis determinantes da baixa demanda verificada. Apesar dos esforços, o puzzle persiste. Este trabalho amplia a dominância teórica das anuidades sobre ativos não contingentes em mercados incompletos; total na ausência de bequest motives, e parcial, quando os agentes se preocupam com possíveis herdeiros. Em linha com a literatura, simulações numéricas atestam que uma parcela considerável do portfolio ótimo dos agentes seria constituída de anuidades mesmo diante de choques de liquidez, bequest motives, e preços não atuarialmente justos. Em relação a um aspecto relativamente negligenciado pela academia, mostramos que o tempo ótimo de conversão de poupança em anuidades está diretamente relacionado à curva salarial dos agentes. Finalmente, indicamos que, caso as preferências dos agentes sejam tais que o nível de consumo ótimo decaia com a idade, a demanda por anuidades torna-se bastante sensível ao sobrepreço (em relação àquele atuarialmente justo) praticado pela indústria, chegando a níveis bem mais compatíveis com a realidade empírica.

Contributions to the Theory of Optimal Tests

This paper considers tests which maximize the weighted average power (WAP). The focus is on determining WAP tests subject to an uncountable number of equalities and/or inequalities. The unifying theory allows us to obtain tests with correct size, similar tests, and unbiased tests, among others. A WAP test may be randomized and its characterization is not always possible. We show how to approximate the power of the optimal test by sequences of nonrandomized tests. Two alternative approximations are considered. The rst approach considers a sequence of similar tests for an increasing number of boundary conditions. This discretization allows us to implement the WAP tests in practice. The second method nds a sequence of tests which approximate the WAP test uniformly. This approximation allows us to show that WAP similar tests are admissible. The theoretical framework is readily applicable to several econometric models, including the important class of the curved-exponential family. In this paper, we consider the instrumental variable model with heteroskedastic and autocorrelated errors (HAC-IV) and the nearly integrated regressor model. In both models, we nd WAP similar and (locally) unbiased tests which dominate other available tests.

Central bank balance sheet concerns and credible optimal escape from the Liquidity trap

I show that when a central bank is financially independent from the treasury and has balance sheet concerns, an increase in the size or a change in the composition of the central bank's balance sheet (quantitative easing) can serve as a commitment device in a liquidity trap scenario. In particular, when the short-term interest rate is up against the zero lower bound, an open market operation by the central bank that involves purchases of long-term bonds can help mitigate the deation and a large negative output gap under a discretionary equilibrium. This is because such an open market operation provides an incentive to the central bank to keep interest rates low in future in order to avoid losses in its balance sheet.