Hello I'm using the
MatchIt package in R
I have a total of unmatched 116 treated cases and 462 unmatcehd non-treated case
with the command
mod_match_logit = matchit(f.build("treatement_yes_or_no", covariates), method = "nearest", distance = "logit", data = df, caliper = 0.05, ratio = 3)
I get then a result of 91 matched treated cases with 248 matched non treated cases. What I don't understand is that, with a 3:1 matching, I should have 91*3 = 273 matched non treated cases (and not 248). Per default is the command
replace set to
MatchIt, so it doesn't explain the difference for me. What am I missing?