Hello,

I am trying to merge variables from the original Demographic and Health surveys (DHS) with the IPUMS-DHS data. The unique identifier in both datasets is "caseid". My master dataset (IPUMS) has a caseid and year variable (2005 and 2014) plus all other measures. In the original DHS they also have caseid, year variable (2005 ONLY) plus another variable which I would like to merge in.



I run the following command using my master dataset:

Code:
merge m:1 caseid year using "original DHS data file"
Which returns the following:

Code:
    Result                           # of obs.
    -----------------------------------------
    not matched                       126,364
        from master                   106,890  (_merge==1)
        from using                     19,474  (_merge==2)

    matched                                 0  (_merge==3)
    -----------------------------------------
Nothing has been matched. I have tried m:1 and 1:1 and I get the same result. Can anyone advise?