Henriques, Paulo LopesSarmento, JoaquimMartins, João Maria Casadinho de Sá2012-06-202012-06-202012-05Martins, João Maria Casadinho de Sá. 2012. "A fiscalidade e a estrutura de financiamento das empresas". Dissertação de Mestrado. Universidade Técnica de Lisboa. Instituto Superior de Economia e Gestão.http://hdl.handle.net/10400.5/4449Mestrado em Ciências EmpresariaisThis document aims to review the different theories based around the optimum capital structure of firms and afterwards, discuss the theory presented by Miller in his work published in 1977. His thesis is applied and tested in this document through the analysis of the Portuguese economy as well as the stock market evolution, in an evaluation process of links and dependencies between the capital structure indicators of firms listed in PSI20 and their respectful market values. An analogy between economical cycles, profit retention policies and capital structure of these businesses is also brought forth. The observed results were conclusive in regards to these links.pormaster thesis