MatchIt preprocesses data by selecting approximate matched
samples of the treated and control groups with similar
covariate distributions, drawing on a large variety of matching
methods.  After preprocessing data with MatchIt, whatever
standard parametric technique one might have used without
preprocessing can be used, but the results will be far less
model dependent.

MatchIt: Nonparametric Preprocessing for Parametric Casual
Inference
Daniel Ho <daniel.e.ho@gmail.com>, Kosuke Imai
<kimai@Princeton.Edu>, Gary King <king@harvard.edu>, Elizabeth
Stuart <stuart@stat.harvard.edu>
cem, optmatch, Matching, nnet, rpart, mgcv, WhatIf
MatchIt selects matched samples of the the original
treated and control groups with similar covariate distributions
-- can be used to match exactly on covariates, to match on
propensity scores, or perform a variety of other matching
procedures.

Nonparametric Preprocessing for Parametric Casual Inference
cem, optmatch, Matching, nnet, rpart, mgcv, WhatIf, R.rsp
Selects matched samples of the original treated and
control groups with similar covariate distributions -- can be
used to match exactly on covariates, to match on propensity
scores, or perform a variety of other matching procedures.  The
package also implements a series of recommendations offered in
Ho, Imai, King, and Stuart (2007) <DOI:10.1093/pan/mpl013>.

R (>= 2.7), MASS, optmatch, Matching, WhatIf, nnet, rpart, mgcv

c(
person("Daniel", "Ho", , "daniel.e.ho@gmail.com", c("aut")),
person("Kosuke", "Imai", , "kimai@Princeton.Edu", c("aut", "cre")),
person("Gary", "King", , "king@harvard.edu", c("aut")),
person("Elizabeth", "Stuart", , "stuart@stat.harvard.edu", c("aut")),
person("Alex", "Whitworth", , "whitworth.alex@gmail.com", c("ctb"))
)
cem, nnet, optmatch, rpart, mgcv, WhatIf, R.rsp, testthat
Daniel Ho [aut],
Kosuke Imai [aut, cre],
Gary King [aut],
Elizabeth Stuart [aut],
Alex Whitworth [ctb]

Nonparametric Preprocessing for Parametric Causal Inference
cem, nnet, optmatch, rpart, mgcv, WhatIf, R.rsp, testthat,
rgenoud