Hello,

I found a post on this subject but the solutions posted do not work for me.

My master data set has 276 variables and 41,000 observations. Two of the variables are an MFIID and MFIName, however these are the same for multiple observations but with different fiscal years.
My secondary dataset has 5 variables and 3115 observations. It also has the variables MFIID and MFIName but has a single observation for each one (to show the country and region of the institution).

I am attempting to combine the two datasets so that each observation in my master dataset includes the corresponding data for country and region from my secondary dataset. I have tried merge 1:m, merge 1:1 and merge m:1 but I always receive the same error message: r(459); variables MFIID MFIName do not uniquely identify observations in the using data.

Is there a way to merge datasets without having a unique identifier?

Thank you