Hi,
I want to test the did-assumption of pre-treatment parallel trends.
I have already visually displayed the pre- and post-treatment trends in Stata, but I also want to verify with a regression.
My main specification is as follows:
Where I estimate the effects on export from Norway to country j.
xi: ppml ImportTons gdp_imp gdp_exp TREAT POST DID i.year i.importer i.category, cluster (importer)
I want to check in Stata that the pre-treatment trends are parallel and I only have one treatment that happens in 2010, and one control group and one treatment group.
X j,t,p = ß0 +ßt ⋅ YEARt ⋅ TREATj ⋅ pre2010t + year fe + importer fe +product fe + εj,t,p
So YEAR is a dummy variable for each year, TREAT =1 for the treatment group.
How do I create this interaction between of year dummies and the treatment indicator in Stata?
Thank you,
Olivia
I want to test the did-assumption of pre-treatment parallel trends.
I have already visually displayed the pre- and post-treatment trends in Stata, but I also want to verify with a regression.
My main specification is as follows:
Where I estimate the effects on export from Norway to country j.
xi: ppml ImportTons gdp_imp gdp_exp TREAT POST DID i.year i.importer i.category, cluster (importer)
I want to check in Stata that the pre-treatment trends are parallel and I only have one treatment that happens in 2010, and one control group and one treatment group.
X j,t,p = ß0 +ßt ⋅ YEARt ⋅ TREATj ⋅ pre2010t + year fe + importer fe +product fe + εj,t,p
So YEAR is a dummy variable for each year, TREAT =1 for the treatment group.
How do I create this interaction between of year dummies and the treatment indicator in Stata?
Thank you,
Olivia
Comment