Hi,
I am trying to run a synthetic difference-in-differences (as in Arkhangelsky et al, 2021) analysis in a case where I have many units observed over 20 years, but only two treated units. I am trying to use Stata's user-created -sdid- command to do this.
Unfortunately, the command generates a "<istmt>: 3200 conformability error" error message after about 15-20 placebo replications.
Is this a flaw of the command or am I not able to use the synthetic difference-in-differences approach in this data context?
I have attached my data and pasted my analysis code below.
Any help is much appreciated - thanks!
I am trying to run a synthetic difference-in-differences (as in Arkhangelsky et al, 2021) analysis in a case where I have many units observed over 20 years, but only two treated units. I am trying to use Stata's user-created -sdid- command to do this.
Unfortunately, the command generates a "<istmt>: 3200 conformability error" error message after about 15-20 placebo replications.
Is this a flaw of the command or am I not able to use the synthetic difference-in-differences approach in this data context?
I have attached my data and pasted my analysis code below.
Any help is much appreciated - thanks!
Code:
* Load data // use ".../dataex", clear * Declare panel xtset id year * Run analysis sdid dv id year treatment, vce(placebo)
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