Consider the following statements regarding heteroscedasticity in regression analysis:
1) Heteroscedasticity occurs when the variance of the error term is not constant across all levels of the independent variables.
2) If heteroscedasticity is present, OLS estimators remain unbiased but are no longer efficient.
3) Using robust standard errors can help address the issue of heteroscedasticity.
Which of the following options is correct?
1
Only statements 1 and 2 are correct
2
Only statements 1 and 3 are correct
3
Only statements 2 and 3 are correct
4
All statements 1, 2, and 3 are correct
5
Question Not Attempted