Optimal rules for monetary policy in Brazil

This paper presents optimal rules for monetary policy in Brazil derived from a backward looking expectation model consisting of a Keynesian IS function and an Augmented Phillips Curve (ISAS). The IS function displays'a high sensitivity of aggregate demand to the real interest rate and the Phillips Curve is accelerationist. The optimal monetary rules show low interest rate volatility with reaction coefficients lower than the ones suggested by Taylor (1993a,b). Reaction functions estimated through ADL and SUR models suggest that monetary policy has not been optimal and has aimed to product rather than inflation stabilization.

Hedging options in a garch environment: testing the term structure of stochastic volatility models

This paper develops a methodology for testing the term structure of volatility forecasts derived from stochastic volatility models, and implements it to analyze models of S&P500 index volatility. U sing measurements of the ability of volatility models to hedge and value term structure dependent option positions, we fmd that hedging tests support the Black-Scholes delta and gamma hedges, but not the simple vega hedge when there is no model of the term structure of volatility. With various models, it is difficult to improve on a simple gamma hedge assuming constant volatility. Ofthe volatility models, the GARCH components estimate of term structure is preferred. Valuation tests indicate that all the models contain term structure information not incorporated in market prices.

Um estudo sobre os impactos da surpresa dos indicadores macroeconômicos de atividade e inflação no mercado futuro brasileiro de juros

As diretrizes de política monetária são definidas com base em resultados dos indicadores macroeconômicos divulgados ao mercado periodicamente. Os agentes deste mercado respondem rapidamente às alterações de cenário, com o objetivo de obter lucro ou evitar perdas financeiras expressivas. Com este motivacional, a proposta deste trabalho é avaliar como reage o mercado futuro de juros diante da divulgação de surpresas em determinados indicadores macroeconômicos, propondo um indicador de surpresa agregado para prever os impactos causados. Através dos dados extraídos da Bloomberg e da BM&F Bovespa, foi construída uma base de dados simplificada pela adoção de premissas para mensuração do impacto das surpresas divulgadas no preço do DI Futuro. A padronização dos parâmetros, a realização dos testes de média e as regressões otimizadas pelo método OLS possibilitaram ponderar os indicadores econômicos de acordo com a oscilação que os mesmos causam a este mercado. Por fim, o teste de comparação mostrou que o indicador de surpresa proposto foi mais eficiente nas previsões da reação do mercado do que um indicador que pondere de forma igualitária todos os indicadores macroeconômicos.

Simulation-based smoothing and filtering in factor stochastic volatility models : two econometric applications

In this article we use factor models to describe a certain class of covariance structure for financiaI time series models. More specifical1y, we concentrate on situations where the factor variances are modeled by a multivariate stochastic volatility structure. We build on previous work by allowing the factor loadings, in the factor mo deI structure, to have a time-varying structure and to capture changes in asset weights over time motivated by applications with multi pIe time series of daily exchange rates. We explore and discuss potential extensions to the models exposed here in the prediction area. This discussion leads to open issues on real time implementation and natural model comparisons.

Simulation -based smoothing and filtering in factor stochastic volatility models : two econometric applications (July-2001)

The past decade has wítenessed a series of (well accepted and defined) financial crises periods in the world economy. Most of these events aI,"e country specific and eventually spreaded out across neighbor countries, with the concept of vicinity extrapolating the geographic maps and entering the contagion maps. Unfortunately, what contagion represents and how to measure it are still unanswered questions. In this article we measure the transmission of shocks by cross-market correlation\ coefficients following Forbes and Rigobon's (2000) notion of shift-contagion,. Our main contribution relies upon the use of traditional factor model techniques combined with stochastic volatility mo deIs to study the dependence among Latin American stock price indexes and the North American indexo More specifically, we concentrate on situations where the factor variances are modeled by a multivariate stochastic volatility structure. From a theoretical perspective, we improve currently available methodology by allowing the factor loadings, in the factor model structure, to have a time-varying structure and to capture changes in the series' weights over time. By doing this, we believe that changes and interventions experienced by those five countries are well accommodated by our models which learns and adapts reasonably fast to those economic and idiosyncratic shocks. We empirically show that the time varying covariance structure can be modeled by one or two common factors and that some sort of contagion is present in most of the series' covariances during periods of economical instability, or crisis. Open issues on real time implementation and natural model comparisons are thoroughly discussed.

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 .

Reality check for volatility models

Asset allocation decisions and value at risk calculations rely strongly on volatility estimates. Volatility measures such as rolling window, EWMA, GARCH and stochastic volatility are used in practice. GARCH and EWMA type models that incorporate the dynamic structure of volatility and are capable of forecasting future behavior of risk should perform better than constant, rolling window volatility models. For the same asset the model that is the ‘best’ according to some criterion can change from period to period. We use the reality check test∗ to verify if one model out-performs others over a class of re-sampled time-series data. The test is based on re-sampling the data using stationary bootstrapping. For each re-sample we check the ‘best’ model according to two criteria and analyze the distribution of the performance statistics. We compare constant volatility, EWMA and GARCH models using a quadratic utility function and a risk management measurement as comparison criteria. No model consistently out-performs the benchmark.

Aggregate vs disaggregate data analysis: a paradox in the estimation of money demand function of Japan under the low interest rate policy

We investigate the issue of whether there was a stable money demand function for Japan in 1990's using both aggregate and disaggregate time series data. The aggregate data appears to support the contention that there was no stable money demand function. The disaggregate data shows that there was a stable money demand function. Neither was there any indication of the presence of liquidity trapo Possible sources of discrepancy are explored and the diametrically opposite results between the aggregate and disaggregate analysis are attributed to the neglected heterogeneity among micro units. We also conduct simulation analysis to show that when heterogeneity among micro units is present. The prediction of aggregate outcomes, using aggregate data is less accurate than the prediction based on micro equations. Moreover. policy evaluation based on aggregate data can be grossly misleading.

The BRICS: some historical experiences, growth challenges and opportunities

The acronym BRICS was a fad among the media and global investors. Now, the acronym sounds passé. However, the group of countries remains important, from both political and economic reasons. They have a large aggregate size, 28% of the global GDP and 42% of the world’s population, high growth potential due to the current significant misallocation of resources and relatively low stock of human capital, structural transformation is in progress and one of them, China, is taking steps to become a global power and a challenger to the US dominance. This paper provides a brief overview of the five economies, Brazil, Russia, India, China and South Africa. We focus on some aspects of their history, the Chinese initiatives in international finance and geopolitical strategic moves, their growth experience and structural transformation over the last 35 years, trade and investment integration into the global economy and among themselves, the growth challenges faced by their economies and the potential gains to the Brazilian economy from a stronger integration with the other BRICS. In association with its efforts to be a global power, China aims to become a major player in global finance and to achieve the status of global currency for the renminbi, which would be the first currency of an emerging economy to attain such position. Despite the similarities, the BRICS encompass very diverse economies. In the recent decades, China and India showed stellar growth rates. On the other hand, Brazil, Russia and South Africa have expanded just in line with global output growth with the Russian economy exhibiting high volatility. China is by far the largest economy, and South Africa the smallest, the only BRICS economy with a GDP lower than US$ 1 trillion. Russia abandoned communism almost 25 years ago, but reversed many of the privatizations of 90’s. China is still ruled by communism, but has a vibrant private sector and recently has officially declared market forces to play a dominant role in its economy. Brazil, Russia and South Africa are global natural resources powerhouses and commodity exporters while China and India are large commodity importers. Brazil is relatively closed to international trade of goods and services, in marked contrast to the other four economies. Brazil, India and South Africa are dependent on external capital flows whereas China and Russia are capital exporters. India and South Africa have younger populations and a large portion living below the poverty line. Despite its extraordinary growth experience that lifted many millions from poverty, China still has 28% of its population classified as poor. Russia and China have much older populations and one of their challenges is to deal with the effects of a declining labor force in the near future. India, China and South Africa face a long way to urbanization, while Brazil and Russia are already urbanized countries. China is an industrial economy but its primary sector still absorbs a large pool of workers. India is not, but the primary sector employs also a large share of the labor force. China’s aggregate demand structure is biased towards investment that has been driving its expansion. Brazil and South Africa have an aggregate demand structure similar to the developed economies, with private consumption accounting for approximately 70%. The same similarity applies to the supply side, as in both economies the share of services nears 70%. The development problem is a productivity problem, so microeconomic reforms are badly needed to foster long-term growth of the BRICS economies since they have lost steam due a variety of factors, but fundamentally due to slower total factor productivity growth. China and India are implementing ambitious reform programs, while Brazil is dealing with macroeconomic disequilibria. Russia and South Africa remain mute about structural reforms. There are some potential benefits to Brazil to be extracted from a greater economic integration with the BRICS, particularly in natural resources intensive industries and services. Necessary conditions to the materialization of those gains are the removal of the several sources of resource misallocation and strong investment in human capital.

Elections and stock market volatility: evidence in OECD countries and developing countries

Este trabalho estuda se existe impacto na volatilidade dos mercados de ações em torno das eleições nacionais nos países da OCDE e nos países em Desenvolvimento. Ao mesmo tempo, pretende, através de variáveis explicativas, descobrir os fatores responsáveis por esse impacto. Foi descoberta evidência que o impacto das eleições na volatilidade dos mercados de ações é maior nos países em Desenvolvimento. Enquanto as eleições antecipadas, a mudança na orientação política e o tamanho da população foram os factores que explicaram o aumento da volatilidade nos países da OCDE, o nível democrático, número de partidos da coligação governamental e a idade dos mercados foram os factores explicativos para os países em Desenvolvimento.

Options listing and the volatility of the underlying asset: a study on the derivative market function

Os mercados de derivativos são vistos com muita desconfiança por inúmeras pessoas. O trabalho analisa o efeito da introdução de opções sobre ações no mercado brasileiro buscando identificar uma outra justificativa para a existência destes mercados: a alteração no nível de risco dos ativos objetos destas opções. A evidência empírica encontrada neste mercado está de acordo com os resultados obtidos em outros mercados - a introdução de opções é benéfica para o investidor posto que reduz a volatilidade do ativo objeto. Existe também uma tênue indicação de que a volatilidade se torna mais estocástica com a introdução das opções.

Volatility of returns, variations in prices and volume traded: evidence from the main stocks in Brazil

We study the relationship between the volatility and the price of stocks and the impact that variables such as past volatility, financial gearing, interest rates, stock return and turnover have on the present volatility of these securities. The results show the persistent behavior of volatility and the relationship between interest rate and volatility. The results also showed that a reduction in stock prices are associated with an increase in volatility. Finally we found a greater trading volume tends to increase the volatility.

Speculative bubbles and contagion: analysis of volatility's clusters during the DotCom bubble based on the dynamic conditional correlation model

Reviewing the de nition and measurement of speculative bubbles in context of contagion, this paper analyses the DotCom bubble in American and European equity markets using the dynamic conditional correlation (DCC) model proposed by (Engle and Sheppard 2001) as on one hand as an econometrics explanation and on the other hand the behavioral nance as an psychological explanation. Contagion is de ned in this context as the statistical break in the computed DCCs as measured by the shifts in their means and medians. Even it is astonishing, that the contagion is lower during price bubbles, the main nding indicates the presence of contagion in the di¤erent indices among those two continents and proves the presence of structural changes during nancial crisis

Soil CO2 emission as related to incorporation of sugarcane crop residues and aggregate breaking after rotary tiller

O preparo do solo é um dos processos que aceleram a decomposição da matéria orgânica, transferindo carbono para atmosfera, principalmente na forma de CO2. Neste trabalho, investigou-se o efeito do preparo com enxada rotativa sobre as emissões de CO2 do solo durante 02 semanas após o preparo do solo, incluindo-se a presença de resíduos vegetais sobre a superfície. As emissões foram avaliadas por 15 dias após preparo em 3 parcelas: 1) sem preparo e sem palha superficial (SPs); 2) preparo com enxada rotativa sem a presença de palha na superfície (ERs), e 3) preparo com enxada rotativa com a presença de palha superficial (ERc). As emissões provenientes da ERc foram superiores às demais (0,777 g CO2 m-2 h-1), sendo as menores emissões registradas na parcela SPs (0,414 g CO2 m-2 h-1). As emissões totais indicaram que a diferença de C-CO2 emitida à atmosfera corresponde a 3% do total de carbono adicional presente na palha, na parcela ERc, quando comparado à parcela ERs. O aumento da emissão da parcela SPs para ERs foi acompanhado de uma modificação na distribuição do tamanho de agregados, especialmente aqueles com diâmetro médio inferior a 2 mm. O aumento da emissão da parcela ERs para ERc esteve relacionado a uma diminuição da massa de palha na superfície, com fragmentação e incorporação da mesma no interior do solo. Quando se analisa a correlação linear entre emissão de CO2 versus temperatura e umidade do solo, somente a emissão da ERc foi significativamente correlacionada (p<0,05) à umidade do solo.