covs() not allowed in rdrobst

[David Isaksson]

Dear statlists,

I have a very brief question, but I cannot wrap my head around why this doesn't work. For some reason rdrobust doesn't allow me to include covariates with the covs command. It is a continuous variable that work perfectly in all other regressions so it isn't the variable that is the problem. Does anyone knows why this might be the case?

rdrobust depvar runvar, covs(control) 
option covs() not allowed
r(198);

Best

[Scott Merryman]

Is your version up to date?

 
 net install rdrobust, from(https://raw.githubusercontent.com/rdpackages/rdrobust/master/stata) replace

Using the senate data set from RD package works:

. which rdrobust
c:\ado\plus\r\rdrobust.ado
*!version 8.4.0  2021-08-30

. use rdrobust_senate.dta

. rdrobust vote margin, covs(class)

Covariate-adjusted sharp RD estimates using local polynomial regression.

      Cutoff c = 0 | Left of c  Right of c            Number of obs =       1297
-------------------+----------------------            BW type       =      mserd
     Number of obs |       595         702            Kernel        = Triangular
Eff. Number of obs |       361         323            VCE method    =         NN
    Order est. (p) |         1           1
    Order bias (q) |         2           2
       BW est. (h) |    17.847      17.847
       BW bias (b) |    28.257      28.257
         rho (h/b) |     0.632       0.632

Outcome: vote. Running variable: margin.
--------------------------------------------------------------------------------
            Method |   Coef.    Std. Err.    z     P>|z|    [95% Conf. Interval]
-------------------+------------------------------------------------------------
      Conventional |  7.4345     1.4436   5.1500   0.000    4.60516      10.2639
            Robust |     -          -     4.3841   0.000     4.1764      10.9297
--------------------------------------------------------------------------------
Covariate-adjusted estimates. Additional covariates included: 1