It means that the variable Tikld has been defined as numeric in one dataset and character in the other. Depending on its contents, you should convert it to the correct type in the one dataset where it is defined wrongly before merging. Most probably the mistake occurs in proc import, which is a guessing procedure. Since you have no control over the import of Excel files, I suggest you save to csv from Excel and import from there with a data step that sets the correct variable attributes. Using Excel as a transfer file format is, err, sub-optimal, to be polite. Excel and its brethren don't work with tables like databases (and SAS) do, but with sheets of cells that have no structure. proc import tries to do its best to create that structure, but often fails. A properly written data step forces the structure. ... View more