I am currently in a tricky situation. I have a dataset with 83,311 observations and 109 variables. I need to add a categorical variable, "year", to it ("year" is either =2015 or =2016). I have created from other files a new Stata dataset with that one variable, "year", only, also with the same 83,311 observations. How do I incorporate this new variables (with matching observations) into my first dataset, with all the other variables?

Best and happy easter!

Vitor