In this paper we analyse, for some of the largest Portuguese companies, the relevance and validity of several factors considered in the literature as determinants of companies' capital structure (represented by the debt ratio): Size, Growth, Business Risk, Profitability, Assets Composition, Non-Debt Tax Shields, Activity Sector and Ownership Control. Using panel data for the period from 1990 to 1995, we present an empirical study in which we seek to describe the effects that these variables have on companies' debt level in each year of the analysis, trying to identify relationships among the variables, either over time or across companies in the same activity sector. We also analyse the particular effects of each company and each year, that are not included in the explanatory variables of the used models. Although we have reached some results identical to those obtained with other methodologies used at an international level, it is a fact that it did not always happened like that. In our opinion, this was due to the specific characteristics of the companies in our sample and, in general terms, to those of the Portuguese (financial) market.
capital structure; determinant factors; panel data analysis
