This paper builds a real business cycle (RBC) model with government, aiming to replicate key features of the Brazilian economy. I first calibrate and then I use Bayesian methods to estimate the model for Brazil, with 20 years of quarterly aggregate data. Contrary to the conventional knowledge, I find mixed evidence on the pro-cyclicality of the fiscal policy in Brazil. Moreover, the results suggest that tax rate changes have been used to counter changes in the level of government indebtedness, however in a small degree if compared to other international evidence.

Sample preparation of polymers for halogen determination requires special attention because they are difficult to bring into solution and due to the risk of analyte losses when using acid digestion. A method using microwave-induced combustion (MIC) was optimized for accurate determination of halogens in polymeric parts obtained in waste of electrical and electronic equipment. Results were compared with those by using microwave-assisted extraction (MAE) with alkaline solution and microwave-assisted wet digestion (MAWD) using concentrated nitric acid, which are common choices for sample preparation. In this particular case, the MAE method was not suitable and underestimated results were obtained, showing the necessity for the complete digestion. Even with the use of MAWD under high temperature and pressure, incomplete digestion and high acid content were obtained, which were unsuitable for analysis and resulted in poor recovery. Only by using MIC (diluted ammonia as absorbing solution) acceptable recoveries (95 to 104%) and agreement with certified values for the certified reference materials (CRMs) of polymers were obtained. Thus, a suitable method for all halogen to be determined by ion chromatography (IC) or inductively coupled plasma mass spectrometry (ICP-MS), with the exception of F, was obtained in agreement with the requirements by the Restriction of the Use of Certain Hazardous Substances (RoHS) European directive.

In this paper, a feasible method was proposed for the chlorine and fluorine determination in eye-pencil samples using ion chromatography (IC). The microwave-induced combustion (MIC) was used to digest up to 200 mg of a sample, with 50 mg of microcrystalline cellulose as a combustion aid and only water for analytes absorption. Cl and F recoveries were 105 ± 1 and 93 ± 5%, respectively, when standard solutions were used in the recovery tests. Certified reference materials (CRM) were also digested mixed to the sample, and no significant difference between the obtained results and the certified values was observed. Precision was assessed in terms of repeatability and intermediate precision, with relative standard deviations (RSD) lower than 9%. Limits of detection (LOD) for Cl and F were 37 and 4 mg kg-1, respectively. Ultrasound-assisted extraction (UEA) was also evaluated; however, the results were not satisfactory. The proposed method was suitable for Cl and F determination in eye-pencil because it proved to be accurate, precise and safe, and also minimized waste generation and had high throughput.

Dry ashing, dissolution in aqueous medium or wet digestion methods were evaluated for sample preparation of shampoo for the subsequent indirect determination of sulfur by UV-Vis spectrophotometry. Among the sample preparation methods evaluated, microwave-assisted wet digestion using 7 mol L-1 HNO3 was the most suitable method for this purpose. Accuracy of the proposed method was evaluated by recovery test using standard solution, and the recovery was about 96%. Moreover, for comparison of results, S (as SO42-) was also determined by ion chromatography, after microwave-assisted wet digestion using concentrated HNO3, and no significant difference was observed between the obtained results (according to the t-test for a 95% confidence level, p = 0.288). Relative standard deviations were always lower than 10% and the limit of detection was 0.007% w/v. Finally, the proposed method was applied for analysis of sixteen shampoos used to many types of hair, from different brands produced in Brazil, and the concentration of S ranged from 0.78 to 2.82% w/v.

Nesse artigo a ideia do consumo regra de bolso, em que algumas famílias não se comportam de acordo com a Hipótese da Renda Permanente, é aplicada a uma estrutura de uma pequena economia aberta. Apresentamos um modelo de conta corrente com indivíduos se comportando pela regra de bolso e com formação de hábitos. O modelo é estimado separadamente com dados de cinco países. Estamos particularmente interessados em dois parâmetros do modelo: a razão da renda agregada doméstica aferida por indivíduos regra de bolso, e o coeficiente de formação de hábitos. Utilizando dados de conta corrente, os resultados obtidos sugerem que o comportamento regra de bolso tem um papel importante na economia. Ademais, os coeficientes de formação de hábitos estimados são em geral pequenos e não-significantes.

In this paper the idea of rule of thumb consumption, in which some households do not behave according to the Permanent Income Hypothesis, is applied to a small open economy framework. A model of current account with rule of thumb individuals and habit formation is presented and estimated for five different countries. Two parameters of the model are of particular interest: the share of domestic income that accrues to rule of thumb individuals and the coefficient of habit formation. Using current account data, the results obtained here support the view that rule of thumb behavior plays a major role in the economy. Moreover, the estimated habit formation coefficients are mostly small and nonsignificant.

Este artigo avalia empiricamente o sinal da relação entre investimento e incerteza no Brasil, utilizando o arcabouço dos modelos com custo de ajustamento quadrático. O artigo mostra que essas variáveis são negativamente relacionadas na economia brasileira. A implicação é que o nível de investimento pode ser aumentado com a adoção de uma política macroeconômica sustentável capaz de evitar choques que geram incerteza, como grandes desvalorizações no câmbio ou moratórias nas dívidas interna e externa. Propõe, ainda, um método para estimar o modelo com custo de ajustamento quadrático quando a variável endógena é I(2) e as variáveis exógenas são I(1). Dado que o estoque de capital é tipicamente uma variável I(2), o procedimento econométrico parece particularmente apropriado para modelos de investimento.

This paper assesses empirically the sign of the uncertainty-investment relation in Brazil within a quadratic adjustment cost model. It is shown that these variables are negatively related in the Brazilian economy. The implication is that investment can be enlarged with the adoption of a sustainable macroeconomic policy that rules out uncertainty-yielding shocks, such as a huge devaluation in domestic currency, or defaults in internal and external debts. The paper also proposes a method for estimating the quadratic adjustment cost model when the endogenous variable is I(2) and the forcing variables are I(1). Since capital stock is typically an I(2) variable, the econometric insight seems particularly suited for models of investment.