Hi Statalist.

I want to set a single base level for an interaction between two categorical variables marital status (de facto or married) and education level (edlev1 ... edlev5) - as a de facto couple with the lowest level of education (i.e. base: de facto # edlev1) - with which to compare all other categories as I want to understand the effect of both increasing levels of education and marital status, not just one or the other. At present, if I run the interaction:
Code:
i.marstat#i.edlev
Stata will create multiple base levels (de facto"# edlev1 ... edlev5), e.g. "married # edlev1" compared with base "de facto # edlev1", then "married # edlev2" with the base of "de facto # edlev2", "married # edlev3" with the base of "de facto # edlev3", etc. Is it possible to compare all options back to a single base level of "de facto # edlev1"? If so, how can I code that such that I can apply it to categorical variables with more than two categories.

Thank you in advance.

N.B. I did not provide sample data as I thought this is a fairly generic coding issue, though I can do so if needed.
Stata v.15.1. I'm not sure it matters, but I am using Cox Regression analysis.