Suppose I am running a standard OLS multiple regression on the incomes of college graduates 10 years after graduation. I include a mess of individual-specific predictors (e.g., gender, ethnicity, height, major, GPA at graduation, high school GPA, etc.). But suppose I also want to include variables that are specific to the institution they graduated from, e.g., the U.S. News and World Report national ranking of the university/program they graduated from, a public/private university flag, some kind of university selectivity variable (e.g., admission rate, or yield rate from admissions), etc. So I have an individual response, predicted by variables that are both specific to those individuals and variables that are common to all individuals from a specific group (university), so that every person from the same university has the same values on that set of variables.
What are the foreseeable consequences of such a situation from a regression standpoint, in terms of validity/efficiency of parameter estimates, intelligibility of their interpretation, etc.?