Question

In: Statistics and Probability

(1a) Suppose you wish to predict Yi having observed Xi , but you tie your hands...

(1a) Suppose you wish to predict Yi having observed Xi , but you tie your hands to prediction rules of the form f(Xi) = g1Xi for some constant g1. Derive a formula for coefficient γ1 that minimizes the mean square prediction error M(g1) = E[(Yi − g1Xi) 2 ].

(1b) Now suppose you wish to estimate a regression model of the form Yi = β1Xi +ui . Derive a formula relating β1 and γ1.

(1c) Using your answer to part (b), show that γ1 = β1 if Assumption 1 holds. (d) Propose an estimator of γ1 and show it is consistent. State any additional assumptions.

Solutions

Expert Solution



Related Solutions

1a.) If a constant c is added to each xi in a sample, yielding yi =...
1a.) If a constant c is added to each xi in a sample, yielding yi = xi + c, how do the sample mean and median of the yis relate to the mean and median of the xis? Verify your conjectures. Verify using a made-up example. 1b.) If each xi is multiplied by a constant c, yielding yi=cxi, answer the question of part (a). Again, verify your conjectures. Verify using a made-up example.
Suppose Xi and Yi are all independent (i=1,2,3), where the three Xi are iid and follow...
Suppose Xi and Yi are all independent (i=1,2,3), where the three Xi are iid and follow an Exponential distribution with rate r, while the three Yi are also iid but follow a Normal(μ, σ2) distribution. (a) Write down the joint pdf for the random vector (X1,X2,X3,Y1,Y2,Y3). (b) Find the expected value of the product X1 Y1, i.e., E(X1 Y1), and find Cov(X2, X3).
Suppose Xi and Yi are all independent (i=1,2,3), where the three Xi are iid and follow...
Suppose Xi and Yi are all independent (i=1,2,3), where the three Xi are iid and follow an Exponential distribution with rate r, while the three Yi are also iid but follow a Normal(µ, σ2) distribution. (a) Write down the joint pdf for the random vector (X1,X2,X3,Y1,Y2,Y3). (b) Find the expected value of the product X1 Y1, i.e., E(X1 Y1), and find Cov(X2, X3).
Suppose that Yi=?0+?1Xi+ui and that E[ui|Xi] = 0 and therefore OLS is an unbiased estimator. a)...
Suppose that Yi=?0+?1Xi+ui and that E[ui|Xi] = 0 and therefore OLS is an unbiased estimator. a) Show that Zi=Xi is a valid instrument for Xi , i.e. it is both relevant and exogenous. b) Show that the 2SLS estimator of ?1 using Xi as an instrument for Xi is exactly equal to the OLS estimator of ?1 c) Let Zi=X2i and assume Xi is normally distributed N(?,?²). Is Zi exogenous? Is Zi relevant? Explain how the answer to these questions...
Suppose that the random variable Y1,...,Yn satisfy Yi = ?xi + ?i i=1,...,n. where the set...
Suppose that the random variable Y1,...,Yn satisfy Yi = ?xi + ?i i=1,...,n. where the set of xi are fixed constants and ?i are iid random variables following a normal distributions of mean zero and variance ?2. ?a (with a hat on it) = ?i=1nYi xi  /  ?i=1nx2i is unbiased estimator for ?. The variance is  ?a (with a hat on it) = ?2/  ?i=1nx2i . What is the distribation of this variance?
REGRESSION - USING CALCULATOR 1- You are given data for Xi (independent variable) and Yi (dependent...
REGRESSION - USING CALCULATOR 1- You are given data for Xi (independent variable) and Yi (dependent variable). 2- Calculate the correlation coefficient, r: 3- Calculate the coefficient of determination: 4- Calculate the regression coefficient b1 (the slope): 5- Calculate the regression coefficient b0 (the Y-intercept, or constant): 6- The regression equation (a straight line) is: Problem 2: A researcher is interested in determining whether there is a relationship between shelf space and number of books sold for her bookstore. Shelf...
Suppose that you wish to purchase a car and that your bank is offering to you...
Suppose that you wish to purchase a car and that your bank is offering to you a loan. You wish to explore the nature of this loan and the payments that you would have to make given certain circumstances such as the amount that you borrow. Fortunately, Excel offers a function (PMT) that calculates the payment for a loan based on constant payments and a constant interest rate. The syntax of the function is: PMT(rate, nper, pv) where rate is...
Suppose it is known that the graph of the function y = ax3 + bx2 + cx + d passes through four given points (xi, yi ),
Suppose it is known that the graph of the function y = ax3 + bx2 + cx + d passes through four given points (xi, yi ), i = 1, 2, 3, 4. Write a userdefined function that accepts these four points as input and computes the coefficients a, b, c, and d. The function should solve four linear equations in terms of the four unknowns a, b, c, and d. Test your function for the case where (xi ,...
Suppose we wish to build a multiple regression model to predict the cost of rent (dollars)...
Suppose we wish to build a multiple regression model to predict the cost of rent (dollars) in a city based on population (thousands of people), and income (thousands of dollars). Use the alpha level of 0.05. City Monthly Rent ($) 2018 Population (Thousands) 2010 Median Income (Thousands of Dollars) Denver, CO 998 586.158 45.438 Birmingham, AL 711 212.237 301.704 San Diego, CA 1414 1307.402 61.962 Gainesville, FL 741 124.354 28.653 Winston-Salem, NC 750 239.617 41.979 Memphis, TN 819 646.889 36.535...
Suppose we wish to build a multiple regression model to predict the cost of rent (dollars)...
Suppose we wish to build a multiple regression model to predict the cost of rent (dollars) in a city based on population (thousands of people), and income (thousands of dollars). Use the alpha level of 0.05. A. Is the whole regression model effective in predicting the cost of rent? Use alpha of 0.1. Make sure to show which values you use to make the decision. B. Write down the multiple regression equation using actual names of IVs and DVs. C....
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT