Regards to the topic, I am quite concerned on a suitable methodology as existing literature is more theoretical than quantitative analysis. I was proposed the VAR and VECM, but not convinced. This is because data will be based on the Big Six evaluating the periods before and after the announcement was made.

So was thinking more of the diff in diff method but how may I capture for a control group if all firms would be affected by cap? Any other method you know is suitable, please I kindly await suggestions.