Recently I encountered an issue. I downloaded some data from the Census and Social Explorer and merged them together. Presumably, most of the data from other sources are from the Census but were recoded, renamed or reorganized in more accessible ways. That said, some of them are the same thing but with different variable names, for example, the population of a county. I know "compare" command can compare variables and see if they are identical, but it can only compare two variables. "sum" can list some statistics that compare the variables, but chances are that some variables just happened to have the same mean, sd, min, max, but are not identical. I was wondering if there is an extended version of "compare" that compare all the variables and identify the identical variables. Thanks.