Análise da influência dos desastres ambientais de Mariana e Brumadinho no retorno financeiro das ações da companhia Vale S.A

Abstract

This research aims to analyze the influence of the environmental disasters of Mariana and Brumadinho on the financial return of the shares of the company Vale SA. In order to identify through the announcements of relevant facts such as the Mariana and Brumadinho disasters and the recent news of the penalty of almost R$ 38 billion to the company. The research is quantitative and qualitative. The sample periods analyzed were up to 10, 20 and 30 days before and after each event, taking into account the daily closing value of the shares of Vale S.A. The return was calculated using the logarithmic form. The theoretical reference surveys were collected on the CAPES Theses & Dissertations Catalog and CAPES Periodicals websites. To analyze the data collected from the shares, a descriptive statistics study was initially carried out for each of the relevant facts.In addition, the study of events was carried out using the Chow test and the tests of differences of avarages; The results suggest that only for a 10-day window before and after the Mariana disaster it can be said that there is a statistically significant difference in the stock return, a result that was corroborated by the T test. did not reject the hypothesis that the medians of the groups are equal and that the difference between the median is zero for the case of Brumadinho - MG and for the material fact referring to the agreement of 38 billion referring to repairs in the case of Brumadinho - MG.