I'm conducting an event study on annual executive salaries.
I have a sample of 52 companies which have been given a cartel fine during year 6 (Event year).
For each company, I have a time series of annual salaries for years 1 to 6. I want to test if year 6's salaries are "abnormal", thus significantly different to an expected value.
I define my expected value by forecasting it using linear regression.
Which test statistic would be suitable for this scenario?