Dear Madam/Sir,

I want to estimate two-way fixed effect model for firm and CEO identifier and estimate the following regression and get the error message as follows:

reg ln_audit gafscore mascore big4 cspec ln_nonaudit icw restatement gc auchange merger financing yearend abaccrual ln_at mb lev
> erage roa loss fsalepro sq_segs ar_in special_item ln_tenure y2000-y2015 i.gvkey i.execid
maxvar too small
You have attempted to use an interaction with too many levels or attempted to fit a model with too many variables. You need
to increase maxvar; it is currently 2048. Use set maxvar; see help maxvar.

If you are using factor variables and included an interaction that has lots of missing cells, try set emptycells drop to
reduce the required matrix size; see help set emptycells.

If you are using factor variables, you might have accidentally treated a continuous variable as a categorical, resulting in
lots of categories. Use the c. operator on such variables.
r(907);

Any idea to fix this issue will be highly appreciated.

Sincerely,
HJ