Manipulate the stored coefficients

[Bobby Wood]

Hi, I'd like to manipulate regression results by adding a certain value to each coefficient in the stored matrix. I do a Difference-in-Differences regression and my aim is to plot a graph afterwards where I rotate the coefficents and the corresponding confidence intervals around the linear trend from the pre-treatment period. I saw this in some papers but they used R as I saw from the graphs. Is this also possible in Stata?

[Sebastian Kripfganz]

You would probably need to write a little program and use the command ereturn repost within it.

[Bobby Wood]

You would probably need to write a little program and use the command ereturn repost within it.

Could you give me more advise here? Maybe a short example?

[Andrew Musau]

ssc install erepost, replace

sysuse auto, clear
regress mpg weight disp turn
mat list e(b)
*ADD 1000 TO EACH COEFFICIENT
mat b= e(b) + J(1, colsof(e(b)), 1000)
erepost b=b, rename
mat list e(b)

Res.:

. regress mpg weight disp turn

      Source |       SS           df       MS      Number of obs   =        74
-------------+----------------------------------   F(3, 70)        =     44.47
       Model |  1602.59024         3  534.196747   Prob > F        =    0.0000
    Residual |  840.869218        70  12.0124174   R-squared       =    0.6559
-------------+----------------------------------   Adj R-squared   =    0.6411
       Total |  2443.45946        73  33.4720474   Root MSE        =    3.4659

------------------------------------------------------------------------------
         mpg | Coefficient  Std. err.      t    P>|t|     [95% conf. interval]
-------------+----------------------------------------------------------------
      weight |  -.0059274   .0014326    -4.14   0.000    -.0087847   -.0030701
displacement |   .0055957    .009906     0.56   0.574    -.0141613    .0253527
        turn |  -.1386576   .1793412    -0.77   0.442    -.4963424    .2190272
       _cons |   43.58846   4.964215     8.78   0.000     33.68765    53.48928
------------------------------------------------------------------------------

. 
. mat list e(b)

e(b)[1,4]
          weight  displacement          turn         _cons
y1    -.00592742      .0055957    -.13865764     43.588464

. 
. *ADD 1000 TO EACH COEFFICIENT

. 
. mat b= e(b) + J(1, colsof(e(b)), 1000)

. 
. erepost b=b, rename

. 
. mat list e(b)

e(b)[1,4]
           c1         c2         c3         c4
y1  999.99407  1000.0056  999.86134  1043.5885