Critically analyse the different methodological approaches in the event study literature. Specifically, the focus is on the different equilibrium models used. Commonly used equilibrium models are the mean-adjusted return, market model, capital asset pricing model (CAPM), and the Fama-French 3 factor model. Your discussion should be based on explaining what the models are, how they are performed, and why some models are argued to be more/less appropriate that others. You should also discuss which method is preferred in the mergers and acquisitions literature.