Hi I'm new to STATA. Just completed a survey capturing about 3000+ responses from different city/provinces in China. My DV and IV as follows:

DV - cyber behavior (mch)
IV - predictors of cyber behavior (e.g. perceived vulnerability - ps, perceived severity of threat - pv etc... each predictors comprises of about 5 queries. e.g. ps1 to ps5, pv1 to pv5)
Moderator - cultural index (ctlscore)

I would like to determine how the moderator (ctlscore) affects the IV strength in each province.

I was thinking of

by city: reg dv iv##c.ctlscore

However, one of my committee members told me to use xtreg instead.

xtset city // no time variable
xtreg dv iv##c.ctlscore cityid

** c.cityscore as they're continuous variables, hence the c. Correct?

Can check which approach is more appropriate? Pros and cons? As my data does not capture any time, how can xt commands be suitable? Is it to categorize by city?

Any advice most appreciated!

Kok Wei