Replacing Pis and Cofins - and Why Not the Cpmf? - by a Non-Cumulative Contribution
Cascading taxes are responsible in Brazil for almost 25% of total revenue raised by the three levels of government. This is harmful to the country's economic performance and to her international trade balance. In this paper, the sectoral burdens of Brazilian cascading social contributions, as well as their impacts on exports and imports, are estimated, and their harmful effects on the economy are discussed. Substitution of a value added contribution for the cascading ones is proposed. It is suggested that, in view of urgency and notwithstanding some sacrifice of its quality, the new tax be created simply by means of an ordinary law, without amending the Constitution. Most desirable features of the tax that can be created without changing the terms of the Brazilian Constitution are discussed. The uniform rate necessary to keep tax revenue constant and changes in sectoral tax payments that would arise are estimated.
Abertura comercial brasileira e instabilidade da demanda de importações
Este artigo analisa a politica brasileira de importacoes dos anos 80 e 90, com enfase nas medidas adotadas a partir do processo de liberalizacao comercial e seus efeitos sobre o valor das importacoes. Tambem e apresentado um modelo econometrico para a estimacao da demanda de importacoes no periodo entre 1980 e 1995, baseado no metodo de correcao de erros de Engle-Granger. Nele percebe-se a existencia de uma ruptura da estabilidade dos parâmetros associados as variaveis renda e capacidade instalada no primeiro trimestre de 1990. As medidas restritivas as importacoes, tarifarias e nao-tarifarias adotadas nos anos 80, ao mesmo tempo que eliminou o poder explicativo da renda sobre a variacao das importacoes, tornou o desempenho da capacidade instalada extremamente relevante para determinar o seu comportamento. Quando o processo de liberalizacao comercial avanca, a elasticidade-renda de longo prazo se torna significativamente elastica, enquanto a capacidade instalada perde consideravel parcela de seu poder explicativo.
DIFFERENTIAL CALCULUS OF SEVERAL VARIABLES WITH MATHEMATICA OR MAPLE
The use of Computer Algebra Systems (CAS) in Mathematical Laboratories at Engineering Schools is increasing. Therefore, it has become necessary to undertake a new educational approach in the teaching of many mathematical topics. Obviously it is not possible to give the same lectures as in the 1950,s. The CAS allows us to experiment and teach in “a different way”. The students' mathematical knowledge at the beginning of their studies in the University is completely different. Moreover we have fewer credits assigned to Mathematical topics in engineering curriculum. The objective of he authors, professors of different Spanish Universities, is to try to demonstrate a new way to use the CAS, concretely Maple and Mathematica, as a support in the teaching of Differential Calculus of Several Variables. They take advantage of the computer's graphical capacities to sketch the graphs of surfaces defined in explicit, parametric or implicit form. They survey the general topics: limits, partial derivatives, differentiability, chain rule, implicit functions and extreme values. For each topic, they give a few basic instructions of the CAS used; afterwards they give several examples, in increasing order of difficulty, and finally the students must solve exercises and try to establish a general procedure for a quite general problem. In this paper we have included several examples used in this survey.