balanceUV {Matching} | R Documentation |
This function provides a number of univariate balance tests.
Generally, users should call MatchBalance
and not this function
directly.
balanceUV(Tr, Co, weights = rep(1, length(Co)), exact = FALSE, ks=FALSE, nboots = 1000, paired=TRUE, match=FALSE, weights.Tr=rep(1,length(Tr)), weights.Co=rep(1,length(Co)))
Tr |
A vector containing the treatment observations. |
Co |
A vector containing the control observations. |
weights |
A vector containing the observation specific weights. Only use this option when the treatment and control observations are paired (as they are after matching). |
exact |
A logical flag indicating if the exact Wilcoxon test
should be used instead of the test with a correction. See
wilcox.test for details. |
ks |
A logical flag for if the univariate bootstrap
Kolmogorov-Smirnov (KS) test should be calculated. If the ks option
is set to true, the univariate KS test is calculated for all
non-dichotomous variables. The bootstrap KS test is consistent even
for non-continuous variables. See ks.boot for more
details. |
nboots |
The number of bootstrap samples to be run for the
ks test. If zero, no bootstraps are done. Bootstrapping is
highly recommended because the bootstrapped Kolmogorov-Smirnov test
only provides correct coverage even for non-continuous covariates. At
least 500 nboots (preferably 1000) are
recommended for publication quality p-values. |
paired |
A flag for if the paired t.test should be used. |
match |
A flag for if the Tr and Co objects are the result
of a call to Match . |
weights.Tr |
A vector of weights for the treated observations. |
weights.Co |
A vector of weights for the control observations. |
sdiff |
This is the standardized difference which is the mean difference between treatment and control divided by the square root of the average variance (of treatment and control). The entire quantity is then multiplied by a 100. |
mean.Tr |
The mean of the treatment group. |
mean.Co |
The mean of the control group. |
var.Tr |
The variance of the treatment group. |
var.Co |
The variance of the control group. |
p.value |
The p-value from the two-sided weighted t.test . |
var.ratio |
var.Tr/var.Co. |
ks |
The object returned by ks.boot . |
tt |
The object returned by two-sided weighted t.test . |
Jasjeet S. Sekhon, Harvard University, jasjeet_sekhon@harvard.edu, http://jsekhon.fas.harvard.edu/
Hollander, Myles and Douglas A. Wolfe. 1973. Nonparametric statistical inference. New York: John Wiley & Sons.
Sekhon, Jasjeet S. 2004. ``Balance Tests for Matching Estimators.'' Working Paper.
Also see summary.balanceUV
,
ks.boot
, Match
, GenMatch
,
MatchBalance
,
balanceMV
, GerberGreenImai
, lalonde
data(lalonde) attach(lalonde) foo <- balanceUV(re75[treat==1],re75[treat!=1]) summary(foo)