I would like to know from you some advise on how to deal with this issue: I want to explore in a multivariate OLS framework the association between my X and Y. I suspect that my cases are selected in X by their education, and then I need to account for this potential bias in estimating the association btw X and Y (the core focus of my research).
Hence: what procedure should I apply to deal with this situation? I would like to know if it exists a 'gold standard' or different techniques, both to verify if actually education (or whatever other variable) select people within X, and, if so, how to 'purify' the association between X and Y from this selection.
Hope that I was clear enough.
Thanks in advance for you support.