st: New command on SSC: -vmerge- (verbose merge)

[Joe Canner <jcanner1@jhmi.edu>]

Based on a post from a week ago, I created a program called -vmerge- (verbose merge), which, thanks to Kit Baum, is now on SSC (-ssc install vmerge-).  Thanks also to Nicole Boyle, Sergiy Radyakin, Robert Picard, and Phil Clayton for their encouragement and suggestions.

This program is a wrapper for the Stata -merge- command that provides additional details regarding the results of the -update- and -replace- options. It provides a summary table that lists each variable in the master data set and indicates how many variables were affected by the -merge- --update- and -replace- options. This summary table only reflects observations that are in the master data set (_merge==1, 3, 4, and 5). This command sends the -merge- specification and options to the Stata -merge- command without modification, without comment, and without any assessment as to whether using the verbose merge makes sense. This command temporarily duplicates all variables in the master data set, thus requiring additional memory equal to the size of the master data set. An option is available that eliminates the need to use this additional memory, but uses more disk space, takes longer, and results in more cryptic output.

As this is my first attempt at a publically available ado-file, any and all comments, corrections, and suggestions would be most appreciated.

Sincerely,
Joe Canner
Johns Hopkins University School of Medicine


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