Resumen
This research had the aim of comparing the difference on the factors that influenced the level of voluntary disclosure of information related to human resources in the companies that form the IBrX-100 index. The comparison is between the years 2004 and 2013. To determine this level of disclosure in each of the fifty (50) companies in the sample, was calculated the Human Resources Information Disclosure Index (HRIDI), based on the analysis of the management reports. Furthermore, to determine the existence (or not) of significant differences between the factors that influenced the HRIDI, we chose to compare the year 2004 to year 2013. It allowed to test if, after ten years, there were changes on the factors that influenced the HRIDI. The factors evaluated in relation to the influence on the spontaneous disclosure of information regarding human resources were drawn from the academic literature. They are: the company size, profitability, age, nature of business, the size of the firm and the disclosure of social balance. These factors were assessed by regression in the ANCOVA model, based on the perspective of cross-section. Two regressions were made: one with the information relating to 2004 and other with the data of 2013. In conclusion, it was found that in both 2004 and 2013, despite the existence of disparities between the levels of disclosure, the characteristics that influenced the Human Resources Information Disclosure Indexwere the size of companies and the publication of social balance.