Made available in DSpace on 2010-04-20T20:18:30Z (GMT). No. of bitstreams: 0 Previous issue date: 1993-11-09T00:00:00Z / The purpose of the presente máster dissertation is to analyse the impacto of changes in the interest rate on the level of investment; seeking to answer if it is powerful as an instrument of macroeconomic policy to estimulate the autor believes that interest rate affect investment but it is a bad instrument to recuperate the level of investment. To achieve this answer the master dissertation is organized as follow; in the first part a survey with the main theories and recent developments about the investment decision is showed; in the second part the author construct a panel showing the differences between the years and in the last part, two questionaires, applied in different decades, are compared to show the impact of different cenarios. / Trata da influência da taxa de juros na decisão de investir. Apresenta as principais teorias de decisão de investimento. Suporta a conclusão com base em dois questionários aplicados, respectivamente nos anos 1970 e 1990, às cem maiores empresas paulistas, por patrimônio líquido.