Dear Statalist members,

Currently my data size is about 12,000 observations.
The topic of my thesis is trade credit and peer effect,
I already xtset firm year, and include year and industry fixed effects.
My reference paper used standard error cluster by firm,
but when I cluster by firm then the result is not significant.
So I wonder if I can cluster by industry in this case?
And what kind of situation is suitable for use cluster by firm or industry?


Thanks in advance