matching {arm} | R Documentation |
Function for processing matching with propensity score
matching(z, score, replace=FALSE)
z |
vector of indicators for treatment or control. |
score |
vector of the propensity scores in the same order as z. |
replace |
whether the control units could be reused for matching,
default is |
Function for matching each treatment unit in turn the control unit (not previously chosen) with the closest propensity score
The function returns a vector of indices that the corresponding unit is matched to. 0 means matched to nothing.
Jeniffer Hill jh1030@columbia.edu; Yu-Sung Su suyusung@tsinghua.edu.cn
Andrew Gelman and Jennifer Hill. (2006). Data Analysis Using Regression and Multilevel/Hierarchical Models. Cambridge University Press.
# matching first data(lalonde) attach(lalonde) fit <- glm(treat ~ re74 + re75 + age + factor(educ) + black + hisp + married + nodegr + u74 + u75, family=binomial(link="logit")) pscores <- predict(fit, type="response") matches <- matching(z=lalonde$treat, score=pscores) matched <- matches$cnts # balance check! b.stats <- balance(lalonde, treat, matched) print(b.stats) plot(b.stats)