Coarsened Exact Matching- Error message r(3258)

[Onyi Dillibe]

Hi Statalist,

I am having difficulties running the user written Coarsened Exact Matching, “cem" command (http://www.stata-journal.com/sjpdf.h...iclenum=st0176). I keep getting the error message below:


cem matchvar1 matchvar2, treatment(po_status)

Matching Summary:
-----------------
Number of strata: 4
Number of matched strata: 0

0 1 .
All 4460 347 1
Matched 0 0 0
Unmatched 4460 347 1

imbalance(): 3258 <tmp>[1,1] found where void required
<istmt>: - function returned error

I will appreciate any pointers on why I’m getting this error message, and a possible fix. Regarding the treatment variable (po_status), I have 347 treated observations and 4,460 untreated observations. There are no missing observations of the treatment variable.

Thank you!

Onyi

[Melissa Garrido]

Onyi, are matchvar1 and matchvar2 categorical or continuous? Do either of those variables perfectly predict treatment status?

[Tijme Roelofs]

How is the problem solved onyi? I get the same error so it would help me a lot to hear your solution, thanks

[jaimearisty]

I would like to hear how this problem was solved. I also got the same error.