Testing unit root based on partially adaptive estimation

This paper proposes unit tests based on partially adaptive estimation. The proposed tests provide an intermediate class of inference procedures that are more efficient than the traditional OLS-based methods and simpler than unit root tests based on fully adptive estimation using nonparametric methods. The limiting distribution of the proposed test is a combination of standard normal and the traditional Dickey-Fuller (DF) distribution, including the traditional ADF test as a special case when using Gaussian density. Taking into a account the well documented characteristic of heavy-tail behavior in economic and financial data, we consider unit root tests coupled with a class of partially adaptive M-estimators based on the student-t distributions, wich includes te normal distribution as a limiting case. Monte Carlo Experiments indicate that, in the presence of heavy tail distributions or innovations that are contaminated by outliers, the proposed test is more powerful than the traditional ADF test. We apply the proposed test to several macroeconomic time series that have heavy-tailed distributions. The unit root hypothesis is rejected in U.S. real GNP, supporting the literature of transitory shocks in output. However, evidence against unit roots is not found in real exchange rate and nominal interest rate even haevy-tail is taken into a account.

The Brazilian 1994 stabilization plan: an analytical view

The Real Plan has succeeded in stabilizing the Brazilian inflation. The consumer price inflation has been reduced from 11260 percent per year, in June 1994, to an estimate of 8 percent in 1997. The lower inflation resulted in a remarkable income distribution, and in an increased private consumption. The plan managed to control the inflationary effects of the increased demand with some traditional measures: A more liberalized economy, a moving (and overvalued) exchange rate band, high interest rate differentials, and a tight domestic credit policy. The government has, so far failed to accomplish the fiscal adjustment. The price stabilization has largely depended on the current account deficit. However, macroeconomic indicators do not present reasons for concern about the current account sustainability, in the medium-run. The economy may be trapped in a low-growth vicious cycle, represented by a stop-and-go trend, due to the two-way endogencity between domestic saving and growth. Economic growth depends on policies in increase the public sector saving, to secure the privatization of the State enterprises, and to promote investments. The major problem for the government action is, as always, in the political sphere. Approximately 80 percent of the Central Government net revenue are allocated to the social sectors. Consequently, the fiscal reform will hue to deal with the problem of re-designing the public sector’s intervention in the social area. Most probably, it will be inevitable to cut the social area budget. This is politically unpleasant.

The Brazilian credit market for small and medium-sized firms: an adaptive marketing approach

Neste trabalho, o mercado brasileiro de crédito para pequenas e médias empresas (PMEs) é analisado sob a perspectiva do marketing adaptativo, em que se assume que atividades mercadológicas como segmentação, gestão de relacionamento com clientes, apreçamento e desenvolvimento de produtos, são determinadas pela utilidade obtida por agentes de mercado ao atenderem a demanda. Identifica-se que a existência de assimetria de informações e de custos de transação limita e direciona as atividades de marketing no mercado estudado. A partir de uma amostra com 65.535 propostas de crédito, recebidas e avaliadas por um grande banco brasileiro entre janeiro de 2004 e setembro de 2006, estima-se a utilidade do banco em operações de crédito. Adicionalmente, 17.149 transações de empréstimos concedidos pelo banco ao segmento de pequenas empresas entre abril de 2006 e março de 2007, são investigadas. Finalmente, um conjunto de dados com 1,636 registros obtidos pela junção das bases de dados de propostas e de transações mencionados, é analisado em termos das relações entre taxas de juros e os totais de cobertura oferecidas por meio de garantias de crédito. Os resultados revelam a existência de um ambiente de marketing adaptativo, em que os pequenos tomadores de crédito produtivo são racionados, e aceitam pagar taxas de juros mais elevadas do que outros segmentos. Produtos de créditos baseados em garantias líquidas e com altas taxas de juros são desenvolvidos para suprir de maneira oportuna este segmento racionado de pequenas empresas. Ademais, a utilidade do banco em operações de crédito é afetada pela informação privada que captura ao longo de relacionamentos mantidos com seus cientes. Os resultados implicam que o sistema de marketing financeiro brasileiro não desempenha papel formativo no desenvolvimento econômico, que seria de fomento ao crédito produtivo por meio de empréstimos a baixo custo para pequenas e médias empresas. Um sistema formativo de marketing é improvável em um ambiente com informação imperfeita, como o mercado de crédito brasileiro. O estudo traz informações úteis àqueles interessados no desenvolvimento de mercados de crédito produtivo, tais como profissionais de instituições financeiras; agentes responsáveis por políticas públicas e monetárias de fomento ao crédito; e empreendedores de pequeno e médio porte que necessitem de financiamento externo para seus negócios.

A unit root test based on partially adaptive estimation

This paper constructs a unit root test baseei on partially adaptive estimation, which is shown to be robust against non-Gaussian innovations. We show that the limiting distribution of the t-statistic is a convex combination of standard normal and DF distribution. Convergence to the DF distribution is obtaineel when the innovations are Gaussian, implying that the traditional ADF test is a special case of the proposed testo Monte Carlo Experiments indicate that, if innovation has heavy tail distribution or are contaminated by outliers, then the proposed test is more powerful than the traditional ADF testo Nominal interest rates (different maturities) are shown to be stationary according to the robust test but not stationary according to the nonrobust ADF testo This result seems to suggest that the failure of rejecting the null of unit root in nominal interest rate may be due to the use of estimation and hypothesis testing procedures that do not consider the absence of Gaussianity in the data.Our results validate practical restrictions on the behavior of the nominal interest rate imposed by CCAPM, optimal monetary policy and option pricing models.

Stabilization, volatility and the equilibrium real exchange rate

In a general equilibrium model. we show that the value of the equilibrium real exchange rate is affected by its own volatility. Risk averse exporters. that make their exporting decision before observing the realization of the real exchange rate. choose to export less the more volatile is the real exchange rate. Therefore the trude balance and the variance of the real exchange rate are negatively related. An increase in the volatility of the real exchange rate for instance deteriorates the trade balance and to restore equilibrium a real exchange rate depreciation has to take place. In the empirical part of the paper we use the traditional (unconditional) standard deviation of RER changes as our measure of RER volatility.We describe the behavior of the RER volatility for Brazil,Argentina and Mexico.Monthly data for the three countries are used. and also daily data for Bruzil. Interesting patterns of volatility could be associated to the nature of the several stabilization plans adopted in those countries and to changes in the exchange rate regimes .

Temporary exchange rate-based stabilization programs under asset market segmentation

This paper analyses the welfare consequences of temporary exchange rate-based stabilization programs. Differently than previous papers, however, here we assume that only a fraction of households participates in asset market transactions. With this asset market segmentation assumption, the effects of temporary programs on welfare may change drastically. Households with access to the bonds market are able to protect themselves better from the changes in the inflation rate – although at the cost of a distortion in their consumption path. As a consequence, they may decrease their inflation tax burden – which would increase for the other group of households. By the other side, when these agents that lack the access to the asset markets are credit constrained, they may welcome the program, since the government Is temporally reducing the inflation tax they have to pay. The temporary program could end up benefiting both groups, what could help to understand their popularity.

Robustness and stabilization properties of monetary policy rules in Brazil

Based on three versions of a small macroeconomic model for Brazil, this paper presents empirical evidence on the effects of parameter uncertainty on monetary policy rules and on the robustness of optimal and simple rules over different model specifications. By comparing the optimal policy rule under parameter uncertainty with the rule calculated under purely additive uncertainty, we find that parameter uncertainty should make policymakers react less aggressively to the economy's state variables, as suggested by Brainard's "conservatism principIe", although this effect seems to be relatively small. We then informally investigate each rule's robustness by analyzing the performance of policy rules derived from each model under each one of the alternative models. We find that optimal rules derived from each model perform very poorly under alternative models, whereas a simple Taylor rule is relatively robusto We also fmd that even within a specific model, the Taylor rule may perform better than the optimal rule under particularly unfavorable realizations from the policymaker' s loss distribution function.

Labor earnings dynamics in post-stabilization Brazil

This paper analyzes both the levels and evolution of wage inequality in the Brazilian formal labor market using administrative data from the Brazilian Ministry of Labor (RAIS) from 1994 to 2009. After the covariance structure of the log of real weekly wages is estimated and the variance of the log of real weekly wages is decomposed into its permanent and transitory components, we verify that nearly 60% of the inequality within age and education groups is explained by the permanent component, i.e., by time-invariant individual productive characteristics. During this period, wage inequality decreased by 29%. In the rst years immediately after the macroeconomic stabilization (1994

The Sao Paulo stock exchange and the economic stabilization

The inflationary stabilization recently observed in Brazil brings a lot of changes in all aspects of the country’s economic life. In this work we look at the impacts on the stock market, specifically at Bovespa - the São Paulo Stock Exchange. We analyze the leading variables and statistics that describe Bovespa’s behavior, such as volatility and systematic risk, comparing the four years preceding and the four years after 1994, when the Real Plan was implemented. In order to eliminate exogenous influences, we use control series made with international Stock Exchanges Indexes. The results show that after 1994 there was reduced volatility, increased trade volume, reduced efficiency of the Bovespa Index and no changes in systematic risk.