题目

ECON 4818-581 Midterm

多重下拉选择题

Suppose the original model in this question given by , satisfies MLR 1-5. It is known, in the data, exper and tenure are positively correlated. Suppose you add a regressor SSN (social security number of the worker), and run the regression . (a) In this case, which assumption is the most likely to be violated? None of the assumptions (b) Can the OLS estimator be unbiased? unbiased (c) The variance of the OLS estimator is likely to be larger .

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思路分析

We start by restating the scenario and the options to ensure clarity. Question: Suppose the original model in this question satisfies MLR 1-5. It is known, in the data, exper and tenure are positively correlated. Suppose you add a regressor SSN (social security number of the worker), and run the regression (a) In this case, which assumption is the most likely to be violated? (b) Can the OLS estimator be unbiased? (c) The variance of the OLS estimator is likely to be larger. Options: (a) None of the assumptions, (b) unbiased, (c) larger. Now, we evaluate each option in turn. Option (a): None of the assumptions - One common concern when adding a regressor is whether any of the Gauss–Markov/MLR assumptions are violated. The relevant assumptions include linearity in parameters, random sampling, no perfect multicollinearity, zero conditional mean of the error given regressors, and homoscedasticity (plus standard regression assumptions for inference......Login to view full explanation