How to code the Difference-in-Differences (one event date) in Stata?

[Phuc Nguyen]

Dear Statalist experts,

For example, I am examining the impact of anticorruption on firms' productivity in Myanmar.
I have a variable pt equalling 1 if this observation is after the enforcement date and pt=0 if it is before the enforcement date. And treatment group is the financial service industry while firms in other industries are control. So the variable for treatment group is financial=1 if firms in financial service industry nad 0 otherwise

Assuming I have the dependent variable is y and the independent variable are x1 x2 x3

I deem that I will regress

xtset firmid year

xtreg y pt#financial x1 x2 x3, fe vce(cluster firmsid)  /*two-way fixed effect and clusterby firms*/

Afterward, I will look at the significance and magnitude of coefficient of "pt" to affirm the impact of laws on y, I am wondering whether it is a correct thought?
Let's say I have the variable for industry is INDC , I wondering how to add the industry fixed effect or indsutry*year fixed effect into the regression?

Thanks in advance.

[Jared Greathouse]

Data example please.