Hello,

One newbie question but I'm stuck on this basic task. I'm pooling two datasets from two different years and have successfully added observations to the main dataset through the command "append". However, when running my regressions I would like to control for the survey year. But I don't know how to since there is no such variable due to their originally cross-sectional nature? Do I need to create a variable that includes the entire dataset and then control for it? How do I do that? There is a variable of the respondents' ID but there are thousands of observations in that one.

Thankful for any ideas!