NOTE: THE VERSION IN DEVELOPMENT IS HERE. ISSUES SHOULD BE SENT THERE. PULL REQUESTS ARE NOT BEING ACCEPTED AT THIS TIME.
MatchIt 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>.