This paper aims at exploring some hypothesis to explain why real interest rate and bank spread are so high. We argue that the interest rate problem and bank spread problem are connected. More precisely, one important cause of bank spread is the high level of BCB interest rate. So, the solution of interest rate problem, so that it can converge to the levels observed in other countries, will help to reduce bank spread, and doing so contributing to the reduction of the capital cost of the Brazilian economy.

O objetivo deste artigo é discutir e analisar a relevância da dívida pública, particularmente de sua duração, como um importante canal de transmissão da política monetária. Procura-se argumentar que a característica do mercado de dívida pública no Brasil, fortemente concentrado em títulos pós-fixados, especialmente em Letras Financeiras do Tesouro, retira parte da eficácia da política monetária. Dado que as LFTs são títulos com valor de face imune a variações na taxa de juros e que aproximadamente metade da dívida pública está indexada a tais títulos, um importante canal de transmissão da política monetária, o efeito riqueza, é interrompido.

The objective of this article is to argue and to analyze the relevance of the public debt, particularly of its duration, as an important monetary policy mechanism transmission. It is looked to argue that the characteristic of the public debt market in Brazil, strong concentrated in post-fixed assets, especially in Treasure's Financial Letters, removes part of the monetary policy effectiveness. Considering that the LFTs are assets with face value immune to variations in the interests rate and that approximately half of public debt is index to such assets, an important mechanism of monetary policy transmission, the wealth effect, is interrupted.