Do the coefficients on the small class indicator change if additional independent variables are added to the model? What does this tell you about selection on observables?
Description of the data The data base “Star13.dta” covers students who took part in the STAR experiment at some point between kindergarten and 3rd grade. It contains information on their birth year, race, treatment assigned, and on their learning outcomes. Further, information on their teachers’ backgrounds is available: Id Fictitious student identification number Sex Sex […]