Dear Statlist,

I am conducting an event study for a sample of 153 companies announcing layoffs between 2008 and 2016.

I am using a regression between cumulativ abnormal return (CAR) and different variables using the command.
regress CAR variables1 variable2 etc, r
(The different variables correspond to firm performance, size of the firm, dummy variable if the firm belong to the sector service or no ...)

However I was thinking about the relevance of using industry or year firm fixed effect using the following command
regress CAR variables1 variable2 i.INDUS i.year, r

I was thinking of industry fixed effect since 50% of the companies belong to the same industry.

However I am not sure I am having the right reasoning.

I have found a lot of information about panel data fixed effect but not much about fixed effect in OLS regression that's why I am asking.

Thanks a lot,

Najiba