Do ESG disclosures mitigate investors’ reaction on mining disasters? Evidence from Brazil

The purpose of this paper is to examine the investors´ reaction to the largest ecological disasters –Samarco (2015) and Brumadinho (2019)– occurred in Minas Gerais (Brazil). Applying a short-term event study analysis, we test the stock and Credit Default Swap (CDS) market´s on the mining sector. Moreover, a cross-sectional analysis is performed testing the effect of ESG disclosures on the market reaction –in terms of Cumulative Abnormal Returns, CAR– on the competitors of Vale S.A., the company involved in such ecological catastrophes. Our findings show a statistically significant reaction in both events. Investors´ react negatively and immediately in the case of Vale for both events; CARs are statistically significant for the shorter windows. However, investors react differently in the mining sector sample –excluding Vale–. While CARs are negative in Samarco, investors do so positively in the case of Brumadinho. In that sense, investors seemed as if they switch their perceptions from this first event –Samarco–in comparison to the most recent one –Brumadinho– rewarding the increase of ESG disclosures in the meantime and mitigating a negative contagion effect in the mining sector. The impact on the CDS market is also found positive in mining sector.