Hi all, I am an undergraduate student who is currently doing an assignment. I am now facing a few problems which are:-
1) Age is usually a positive return to wage, but in my regression output, that's not the case. How should I interpret the signs and its coefficient then? And regarding the age^2, which is to test the concavity will also be odd. Any thought?
2) Higher is believe to be the proxy for innate ability and instrument variable (mother educated is used to solve endogeneity), is it correct the way I do it?
3) The t-value for certain variables are relatively low and insignificant, is interpreting those variables are still relevant and appropriate?
Thank you in advance for your kind assistance! Stata/Statistics Guru, please help me out!