Thank you for your comment. I believe there are several important differences between the investments in the pre-salt oil and the investments in the ethanol industry in the past. Some of these differences that come to my mind:
a) Oil is a non-renewable energy source, but ethanol is;
b) as so, oil use has negative externalities to the environment, but ethanol has positive ones;
c) The historical context behind the decision to develop the ethanol industry was very distinct from the one in recent years; at that point, the energy crises behind the OPEP oil price control was an important driver of the decision to invest in the ethanol industry; more recently, the automobile industry in Brazil saw the opportunity to develop flex fuel vehicles based on its competitiviness compared to gasoline, without explicit incentives from the government, which could have decreased our oil dependence. Also, there is an increasing international and national pressure to take climate change seriously, what means to reduce the use of fossil fuel energy. All these are evidences that the timing and incentives to invest in ethanol and pre-salt oil were (or are) very different;
So, in summary, there are several differences behind costs and benefits of these choices (ethanol and pre-salt), what make it very hard to compare the public investments on them.
I totally agree with you that there are too many reactive short run interferences on these sectors, and very few (or none) long run strategic planning.

The model we have used does not have detailed representation of a city of small region near the oil exploration. In this regard, you may find the paper by Haddad and Giuberti (2011), cited in our study, useful to answer your questions. Below is the full citation of this paper:

HADDAD, E.A.; GIUBERTI, A.C. Economic iImpacts of pPre-sSalt on a rRegional eEconomy: The Case of Espirito Santo, Brazil.- Jönköping, Sweden. 50th Anniversary European Congress of the Regional Science Association International, 2011

Thank you for your comment. The results we have found in our research suggest that the overall costs of the pre-salt oil exploration (including the opportunity costs and the competition for resources with other sectors) are too high compared to the potential benefits it will bring to our economy. Considering the several uncertainties related to the pre-salt oil (size of reserves, costs to perform deep-oil drilling technology, future oil prices, possible future constraints to CO2 emissions), our suggestion, based on our findings, would be to wait a decade before investing massively in the exploration of this resource. As this suggestion is hard to be taken at this point, we recommend investments on research and technology to decrease the costs of deep-oil exploration. Anyway, the choice to explore the pre-salt oil is not a movement toward development of clean energy.