Hi,

I am not very familiar with Stata. So far I have read a lot but I am still having issues.
My dependent variable is cars (=cumulative abnormal returns of firms), the key independent variable is the number of blockholders (=large shareholder).
There are more than 8 categories of blockholders at different levels (5%/10%/20%).

The cumulative abnormal returns were already calculated (even study). So now there are different cumulative abnormal returns for each firm, in total there are 480 observations. Each firm may or may not reappear in the sample over the years. The time period is 2012-2020. The cross pooled could be a good choice in this case (I am not very sure).

Would it make sense to add independent variable categories all ine one equation? (I have not accounted for year fixed effects yet, since I am not sure if the cross pooled or a simple cross section model apply)

regress cars passive_510 passive_1020 passive_2030 active_510 active_1020 active_2030 lev pm dealvalue roa age size

The problem is that there are many more similar categories. I was wondering if those categories should be added one by one, meaning a new request for each category?

Any advice would be greatly appreciated.