To anyone who uses the Match() function in the Matching library... How do you go about deciding how many matches you will use? With my data, my standard errors generally get smaller if I use more matches.
Speaking of standard errors, when correcting for heteroscedasticity, how many matches do you use (this is the Var.cal option). It seems to me that it might make sense to use the same number of matches as above, but that's just a guess... One more question about Match()... I am calculating a number of SATT's that all have the same covariates (X's) and treatment variables (Tr's). I would like to take advantage of the matching that I do the first time to then quickly calculate the SATT for various different Y's? How can I do that? It would save serious computational time. In case I'm not explaining myself well, in the example below, I would like to calculate satt.Y2 without having to perform the matching all over again, since with more data, the process can be very slow. #make up some data X <- matrix(rnorm(1000*5), ncol=5) Tr <- c(rep(1,500),rep(0,500)) Y1 <- as.vector(rnorm(1000)) Y2 <- as.vector(rnorm(1000)) satt.Y1 <- Match(Y=Y1, X=X1, Tr=Tr, M=1) satt.Y2 <- Match(Y=Y2, X=X1, Tr=Tr, M=1) Thanks, BQ ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
