Yes, you can do nearest neighbor matching with exact restrictions. The option is called
"exact": see
http://gking.harvard.edu/node/4355/rbuild_documentation/Additional_Argument… For
optimal matching, you would have to tweak the inputs to outmatch package by Ben Hansen.
I'm not sure how exactly you would do that, but if you figured it out, then you can
pass those arguments through matchit() function.
Kosuke
Department of Politics
Princeton University
http://imai.princeton.edu
On Sep 14, 2012, at 5:22 PM, Joshua Stewart wrote:
Kosuke Imai,
I am writing in regard to a question I have with your MatchIt R program. Currently I am
trying to analyze a data set with continuous and categorical data. We have achievement
score of students, race, school ID, free and reduced lunch status and treatment or control
status. My question relates to whether or not it is possible to perform an exact match on
categorical data such as race, while at the same time run and optimal or nearest neighbor
match on achievement scores. Thank you very much for your time.
Regards,
Joshua Stewart
Researcher
Mid-continent Research for Education and Learning (McREL)
4601 DTC Blvd, Office 480
Denver, CO 80120
303.632.5508
www.mcrel.org