You can certainly specify more than 2 treatments. The error you’re getting is because
–imbalance- is set up to compare between only two treatment groups. As for the k2k error,
I don’t get that error. However, I do find that k2k does not produce 1:1 matches when
there are more than two treatments.
From: cem-bounces(a)lists.gking.harvard.edu [mailto:cem-bounces@lists.gking.harvard.edu] On
Behalf Of Erik Cleven
Sent: Wednesday, November 11, 2015 3:59 PM
To: cem(a)lists.gking.harvard.edu
Subject: [cem] cem error message
I am attempting to run cem with an ordinal treatment variable that has four values. I get
the following error message:
imbalance(): 3258 <tmp>[1,1] found where void required
<istmt>: - function returned error
r(3258);
A previous reply to someone who also got this error message said to update cem because
there was a bug with the imb function.
I updated and now recieve this message:
NOTE: Treatment has must have only 2 levels to compute distance and weights. In addition,
k2k cannot be used.
Does this mean cem cannot be used with more than 2 treatments? Actually I have a
continuous treatment but I recoded it to a variable with four levels.
Thanks!
Erik
--
Erik Cleven, PhD
Assistant Professor
Department of Politics
Saint Anselm College
100 Saint Anselm Drive
Manchester, NH 03102-1310
E-mail: ecleven(a)anselm.edu
Office Phone: (603) 222-4119
Cell phone: (603) 867-8732