“…Therefore, another direction for further research is the application of long-term event study approaches as they were developed and applied in modern financial economics (e.g., Barber and Lyon, 1997, Kothari and Warner, 1997, Lyon et al, 1999, Mitchell und Stafford, 2000, Ho, 2005. A final direction for further research is the analysis of the robustness of our estimation results concerning the unreliable time series of daily stock returns (particularly regarding the examined renewable energy corporations).…”