show that the OLS estimator can be written as
for y_i = X(beta)+epsilon_i
show that the OLS estimator can be written as for y_i = X(beta)+epsilon_i beta hat-betat. (y...
(a) Suppose A is an n x n real matrix. Show that A can be written as a sum of two invertible matrices. HINT: for any le R, we can write A = XI + (A - XI) (b) Suppose V is a proper subspace of Mn,n(R). That is to say, V is a subspace, and V + Mn.n(R) (there is some Me Mn,n(R) such that M&V). Show that there exists an invertible matrix M e Mn,n(R) such that M&V....
7. When we impose a restriction on the OLS estimation that the intercept estimator is zero, we call it regression through the origin. Consider a population model Y- Au + βίχ + u and we estimate an OLS regression model through the origin: Y-β¡XHi (note that the true intercept parameter Bo is not necessarily zero). (i) Under assumptions SLR.1-SLR.4, either use the method of moments or minimize the SSR to show that the βί-1-- ie1 (2) Find E(%) in terms...
1.Given the Multiple Linear regression model as Y-Po + β.X1 + β2X2 + β3Xs + which in matrix notation is written asy-xß +ε where -έ has a N(0,a21) distribution + + ßpXo +ε A. Show that the OLS estimator of the parameter vector B is given by B. Show that the OLS in A above is an unbiased estimator of β Hint: E(β)-β C. Show that the variance of the estimator is Var(B)-o(Xx)-1 D. What is the distribution o the...
2. Show that W can be written as where U is the number of pairs (Xi, Yj) with X, < Y,. In other words n m U=ΣΣ1," where ,j -(0 otherwise. i=1 j=1 Hint: Let Yi),Ya),... , Ym) be the order statistics for the y-sample. Then U is the number of pairs (Xi,Yu)) with Xi 〈 YG). For fixed j , the number of Xi with Xi 〈 Yu) is just the rank of Y (j) minus the number of...
Problem 2. (26 points) Two random variables X and Y are jointly normally distributed, with E(X)x, EY) y and co-variance Cov(X,Y) = ơXY. To estimate the population co-variance ơXY, a very simple random sample is drawn from the population. This random sample consists of n pairs of random variables {OG, Yİ), (XyW), , (x,,y,)). Based on the sample, we construct sample co-variance SXY as: Ti-1 2-1 1. (4 points) Show Σ(Xi-X) (Yi-Y) = Σ Xix-n-X-Y. 2. (4 points) Find E(Xi...
Please provide step by step solutions and explanations for below questions 1. Derive the OLS estimator for B1 2. Prove that it is unbiased 3. Given the data below Obs y 25 X 2 1 5 2 14 1 4 38 -2 4 3 7 4 23 50 0 5 Compute B using algebra. In other words you are god and you observe u. Now use your ols estimator, as a human who does not observe u, to compute B....
2. (a) (10 marks) Suppose A is an n x n real matrix. Show that A can be written as a sum of two invertible matrices. HINT: for any XER, we can write A= XI + (A - XI) (b) (10 marks) Suppose V is a proper subspace of Mn.n(R). That is to say, V is a subspace, and V #Mnn(R) (there is some Me M.,n(R) such that M&V). Show that there exists an invertible matrix M e Mn.n(R) such...
2. Changing Units Suppose we estimate a standard OLS regression equation on data X and Y and have the standard formulas: 3, L2=(X - X)(Y - Ý) 1=1(X; - X)2 Bo =Ỹ – BX Now suppose that Xi = 1+1.6Z; for some Zi. I.e., suppose that X; were generated by trans- forming some Zi. a) Show that: X = do +ajz for some do, ai (that you need to solve for). b) Plug in the expression from (a) into (X;...
Suppose hat the joint probability distribution of the continuous random variables X and Y is constant on the rectangle 0 < x < a and 0 < y < b for a, b E R+. Show mathematically that X and Y are independent. Hint: (a) Recall JDx "lly f(r, y) dy dx-1 (b) Recall X, Y are independent if ffy fry Suppose hat the joint probability distribution of the continuous random variables X and Y is constant on the rectangle...
Q2 Suppose X1, X2, ..., Xn are i.i.d. Bernoulli random variables with probability of success p. It is known that p = ΣΧ; is an unbiased estimator for p. n 1. Find E(@2) and show that p2 is a biased estimator for p. (Hint: make use of the distribution of X, and the fact that Var(Y) = E(Y2) – E(Y)2) 2. Suggest an unbiased estimator for p2. (Hint: use the fact that the sample variance is unbiased for variance.) Xi+2...