Matching with R

An introduction to matching, such as propensity score matching, using R‘s “optmatch” package. Matching is used to improve balance between groups, typically in observational studies, by creating quasi-experimental strata of similar individuals. We will discuss the theory behind matching and propensity scores, followed by examples using R to perform the matching and judging the match quality, as well as speeding up the matching operation. Basic familiarity with R will be assumed.