If a series, yt, follows a random walk (with no drift), what is the optimal 1-step ahead forecast for y?

A. Close to zero

B. Close to two

C. Close to four

D. Close to one

A. 0 and 0

B. 0 and 3

C. 3 and 0

D. Will vary from one normal distribution to another

A. It will be biased

B. It will be inconsistent

C. It will be inefficient

D. All of a, b and c will be true

A. A white noise process

B. A covariance stationary process

C. An autocorrelated process

D. A moving average process

A. 0.4

B. 0.34

C. 1

D. It is not possible to determine the value of the autocovariances without knowing the disturbance variance

A. A slowly decaying acf, and a pacf with 3 significant spikes

B. A slowly decaying pacf and an acf with 3 significant spikes

C. A slowly decaying acf and pacf

D. An acf and a pacf with 3 significant spikes

A. Biased but consistent coefficient estimates

B. Biased and inconsistent coefficient estimates

C. Unbiased but inconsistent coefficient estimates

D. Unbiased and consistent but inefficient coefficient estimates