I have two spreadsheets with columns of variables. I have a unique
identifier variable consistent in the two spreadsheets, but some columns in
the second spreadsheet that aren't in the first. I would like to merge the
data in the extra columns on the second spreadsheet into the first
spreadsheet based on the unique identifier (so the data corresponds with the
correct row, and isn't just the equivalent of a cut and paste). Does anyone
know how I can do this?