Market players' investment decisions sometimes surprise analysts, especially when projects that are less feasible in financial terms enter first in the market, before more viable projects. One possible explanation is that firms have different expectations concerning the future of the market. In this article we use the Option-Games approach for asymmetric duopolies to analyze investors' decisions in the first auction for wind power in Brazil, held in 2009, in which some less viable firms pushed more viable firms out of the auction. Our analysis shows that even small differences in the investors' views can yield this unexpected result. When uncertainty is low and expectations are symmetric, the outcome is a lower energy tariff as well as a stronger wind industry in Brazil, highlighting the importance of a clear and credible long term governmental policy, not only for the wind industry, but also for any other industry in its early stages.

Este artigo apresenta os resultados de uma investigação bibliográfica e documental sobre avaliação econômica de projetos, identificando o estado da arte e as melhores práticas internacionais nessa área, bem como os critérios atualmente adotados no Brasil. Com base nisso, faz recomendações para a melhoria das metodologias no Brasil, especialmente no que concerne à avaliação dos benefícios de segurança, economias de tempo e desenvolvimento social oriundos de projetos de infraestrutura de transporte.

This article presents the results of an extensive documental research and literature review of worldwide procedures for economic project appraisal, and identifies best practices and state-of-the-art techniques in this area, as well as the criteria adopted in Brazil for this purpose. In the light of international benchmarks, it makes recommendations for improvements in the use of these methods in Brazil regarding the appraisal of safety measures, time savings benefits and social development that result from transportation-related infrastructure projects.