Which of the following is not required for a series to be covariance stationary?
|E( yt )=μ for all t|
|E( yt – μ )( yt – μ )= σ2 < ∞|
|E( yr – μ )( ys – μ )= χr-s for all r, s|
|yt has a normal distribution for all t.|
Which of the following is not true about the Q test?The statistic Q has a normal distribution under the null hypothesis.Q uses the sample size.Q has a χ2 distributionQ is inferior to Q*.
Why are econometricians concerned about the normality of residuals?The assumption of normality is traditional.If residuals are not normal, the disturbance term may not have a zero mean.Non-normality will cause biased coefficient estimates.The assumption of normality is needed to assess the significance of coefficient estimates.