Gvkey and thomson one

[Regina Erasmus]

Hi,

I have 2 dataset that I want to merge
In one dataset I only have the gvkey as firm identifier, the other dataset is obtained from ThomsonOne.
How can I merge these 2 datasets? which identifiers do I need to obtain or do I need a third dataset?

[Phil Bromiley]

Welcome to statalist. You will increase your chances of useful answer by following the FAQ on asking questions – provide Stata code in code delimiters, readable Stata output, and sample data using dataex. Often, people on this list will get sufficiently interested in your problem to actually write you the code to solve the problem, but they can only do this if they have the data readily available and know what you're trying to write.

You should also remember that the immense majority of us are not from your area of research. While I use Compustat and am familiar with gvkey identifiers, others who might answer your question or not. I don't know what identifiers you have in Thompson One.

The standard identifiers are gvkey, cusip, stock tickers, and firm names. You can try to merge on any of these four. Firm names can be particularly tricky because they may be written in different ways. You also have to make sure that the variables in both files are all upper or lower case so you don't get problems of not matching because of case of letters. Note that cusips come in different lengths and sometimes you have to drop a few of the letters or whatever so that they will merge properly. WRDS has some programs and documentation on merging data sets.If you don't have CUSIP and stock tickers in your gvkey data but the other data has one of the two, you may need to download something like a list of tickers gvkeys, and cusips from Compustat or WRDS and use that as a bridge. You would manage that list with both data sets and then be able to merge the two.

Whatever you do, is often a good idea to check that you are getting what you think you are so do look at the observations that appear to merge to make sure that the firm names are in fact the same.