The aimof this paper is to evaluate the impact of the Brazilian petroleumfiscal regime - royalties and special participation tax - on the decision to invest in the development of oil and gas reserves in Brazil. We use the Real Option approach, which considers the value of managerial flexibilities. The model admits the option to wait and the option to abandon. It is simulated the impact of different royalties and special participation tax rates on the threshold price-cost ratios to develop the reserve and to exit the industry. Through a Monte Carlo experiment, it is also estimated a path for both prices and costs with the purpose of assessing the expected revenues to the government under each tax rate. Results suggest that special participation tax, despite its ability to increase revenues, is able to distort the decision to invest as much as (or even more than) royalties, which shows that extending this modality of tax, whose discussion was motivated by the just announced pre-salt discoveries, may not be a good initiative.
