The value of voluntary sustainability reporting - an event study in the financial services industry

This paper investigates the relationship between voluntary sustainability reporting and the stock performance of financial firms. A multi-period event study is used to identify the abnormal return associated with the announcement of the publication of Global Reporting Initiative compliant reports. The findings suggest a negative effect on stock performance – implying that shareholder wealth decreases as a result of this announcement – although weakening over the years. Inspecting the days surrounding the announcement reveal that a negative reaction persists, the latter being simply delayed until after the event, hence hinting at a market disappointed by sustainability reports content.