Consider the following model Yit = a + Ayt-1 + Xie + ut i=1,2,...,N; t=1,...,T U = + V Where -tid (0,0) and vi~iid(0,02) Where represents individual effects and Xit is vector of strictly exogenous variables. 1)Explain why and how does endogeneity problem occur in the above model. 2)What are the consequences of the endogeneity occurred in the above model. 3) Explain which estimators can give consistent and efficient estimates of the parameters when Tis small relative to N. 4) Explain how the above model can be consistently estimated when T is relatively large. (1)