Hello Statalist community,

I am doing an analysis using a diff in diff methodology. As I use Stata 17, I have the opportunity to use the command “didregress” and “estat trendplots”.

However, “estat trendplots” do not provide confidences intervals for the “Observed means” and “Liner-trends model”. It is quite easy to reproduce the “Observed means” graph and to add confidences intervals, but I struggle to even just reproduce the linear-trends model.

Is there a way to reproduce the exact same graph and to add the confidence interval? I think as it is a Stata command, there is no .ado that I could read to understand the process, am I right?



I add the code I use with didregress and an extract of my sample.
didregress (wdds hheadage hheadsex hhmemtotal i.year) (Treat) [pweight=perweight], group(region) time(period)


Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input float(wdds Treat Time Treatment hheadage hheadsex hhmemtotal) int year float period double perweight float region
0 0 1 0 31 1  3 2014 2 1.382122 47
0 0 0 1 36 1  6 2008 1   .83317  2
5 1 1 1 63 1  5 2014 2  .713237  2
0 0 0 0 27 1  4 2008 1  .999403 47
2 0 0 0 86 1 36 2005 0 1.294421 47
1 0 0 0 55 1 11 2008 1   .83317  1
0 0 1 0 24 1  2 2014 2 1.382122 47
0 0 1 0 41 1  3 2014 2  .713237  1
0 0 1 0 26 1  2 2014 2  .713237  1
4 0 1 0 30 1  4 2016 2   .97527 39
0 0 1 0 25 2  2 2016 2  .858931 39
0 0 1 0 28 1  3 2014 2  .863929  1
3 0 1 0 34 1  5 2014 2  .713237  1
2 0 0 0 53 2  8 2013 1  .278545 27
0 0 0 0 29 1  4 2005 0  .885734 47
2 0 0 1 35 1  6 2005 0  .709445  2
0 0 0 1 35 1  5 2011 1 1.283543 50
1 0 1 0 31 1  5 2014 2 1.121907 47
0 0 0 0 33 1  3 2008 0    1.223 27
0 0 0 1 37 1  6 2006 0  .868114 50
end
Thank you in advance.

Regards