Author Question: Suppose that the conditional variance is var(uiXi) = h(Xi) where is a constant and h is a known ... (Read 137 times)

elizabeth18

  • Hero Member
  • *****
  • Posts: 559
Suppose that the conditional variance is var(uiXi) = h(Xi) where  is a constant and h is a known function. The WLS estimator is
 
  A) the same as the OLS estimator since the function is known
  B) can only be calculated if you have at least 100 observations
  C) the estimator obtained by first dividing the dependent variable and regressor by the square root of h and then regressing this modified dependent variable on the modified regressor using OLS
  D) the estimator obtained by first dividing the dependent variable and regressor by h and then regressing this modified dependent variable on the modified regressor using OLS

Question 2

The extended least squares assumptions in the multiple regression model include four assumptions from Chapter 6 (ui has conditional mean zero; (Xi,Yi), i = 1,, n are i.i.d. draws from their joint distribution;
 
  Xi and ui have nonzero finite fourth moments; there is no perfect multicollinearity). In addition, there are two further assumptions, one of which is
  A) heteroskedasticity of the error term.
  B) serial correlation of the error term.
  C) homoskedasticity of the error term.
  D) invertibility of the matrix of regressors.

Question 3

The WLS estimator is called infeasible WLS estimator when
 
  A) the memory required to compute it on your PC is insufficient.
  B) the conditional variance function is not known.
  C) the numbers used to compute the estimator get too large.
  D) calculating the weights requires you to take a square root of a negative number.



AmberC1996

  • Sr. Member
  • ****
  • Posts: 317
Answer to Question 1

Answer: C

Answer to Question 2

Props to you, cheers.

Answer to Question 3

Answer: B



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Certain topical medications such as clotrimazole and betamethasone are not approved for use in children younger than 12 years of age. They must be used very cautiously, as directed by a doctor, to treat any child. Children have a much greater response to topical steroid medications.

Did you know?

Though methadone is often used to treat dependency on other opioids, the drug itself can be abused. Crushing or snorting methadone can achieve the opiate "rush" desired by addicts. Improper use such as these can lead to a dangerous dependency on methadone. This drug now accounts for nearly one-third of opioid-related deaths.

Did you know?

Recent studies have shown that the number of medication errors increases in relation to the number of orders that are verified per pharmacist, per work shift.

Did you know?

Medications that are definitely not safe to take when breastfeeding include radioactive drugs, antimetabolites, some cancer (chemotherapy) agents, bromocriptine, ergotamine, methotrexate, and cyclosporine.

Did you know?

By definition, when a medication is administered intravenously, its bioavailability is 100%.

For a complete list of videos, visit our video library