Hi everyone,

I applied a difference-in-difference approach to one of my research projects. Especially, I want to find out how certain state-level laws("A" laws) affect the unemployment rate of the state. The year the bill was passed is different for each state.

To do a falsification test, I created a placebo treatment variable among non-"A" laws and late adopting "A" laws states with randomly assigned region-specific "A" laws passage dates.

I tried to do simulation 1000 times with randomly assigned treatment years. And then, I want to store the values(Coefficient, P-value, and Confidence level) derived from 1000 regressions.

The dataset would look like this:
year treatment group(state) Treated year
1 1996 1 0
1 1997 1 0
1 1998 1 1
2 1996 0 0
2 1997 0 0
2 1998 0 0
3 1996 1 0
3 1997 1 1
3 1998 1 1
And I want to randomly assign treated years like this and repeatedly do this 1000times.
year treatment group(state) Treated year
1 1996 1 0
1 1997 1 1
1 1998 1 1
2 1996 0 0
2 1997 0 0
2 1998 0 0
3 1996 1 0
3 1997 1 0
3 1998 1 1
or
year treatment group(state) Treated year
1 1996 1 1
1 1997 1 1
1 1998 1 1
2 1996 0 0
2 1997 0 1
2 1998 0 1
3 1996 1 0
3 1997 1 0
3 1998 1 1
I found this code but I don't how could I apply to my context.

Code:
 
 permute treated b= el(r(table), 1, 3) ll = el(r(table),5,3) ul = el(r(table),6,3), ///    saving(SomeOutFile.dta, replace): reg s y x1 x2 treated
Thanks in advance.