'rdbwselect' invertability error

[Vanessa Var]

I am using Stata14 to run RDD. When computing the optimal bandwidth using 'rdbwselect' I get the following error:

Invertibility problem in the computation of preliminary bandwidth below the thresholdInvertibility problem in the computation of bias bandw
> idth (b) below the thresholdInvertibility problem in the computation of bias bandwidth (b) above the thresholdInvertibility problem in th
> e computation of loc. poly. bandwidth (h) below the thresholdInvertibility problem in the computation of loc. poly. bandwidth (h) above t
> he threshold

Can anyone provide me with a solution or provide some insight as to why this might be occurring? The 'rdbwselect' command works fine when using example datasets so I do not believe it's associated with the version of stata I am using. The command I am using is:

rdbwselect ln_price rank if zone_1==1, c(90) p(1) kernel(triangular) bwselect(mserd) scaleregul(1)

[Raissa Fabregas]

Hi Vanessa,

Did you solve this issue?

[Vanessa Var]

Yes, the problem was my running variable. It must be continuous otherwise the rdrobust package will not work correctly.

[Ignacio Garcia Giner]

I seem to get the same error;

Invertibility problem in the computation of preliminary bandwidth below the thresholdInvertibility problem in the computation of bias bandwidth (b) below the thresholdInvertibilit
> y problem in the computation of bias bandwidth (b) above the thresholdInvertibility problem in the computation of loc. poly. bandwidth (h) below the thresholdInvertibility probl
> em in the computation of loc. poly. bandwidth (h) above the threshold

when using the command; rdbwselect MaxofHY070N relativeincome2 fuzzy kernelfn bwselect(msetwo) vce masspoints(check) scaleregul(1)

However, my running variable is continuous, so I do not understand what the problem may be.

Does anyone have an idea as to why I get this error? The 'rdbwselect' command works fine with other running variables (which are also continuous), so I don't understand if that is ultimately the only reason for the error.

[Khawar Afreen]

I also seem to get the same error. anyone give me the solution?