Research Article

Estimation and Properties of a Time-Varying GQARCH(1,1)-M Model

Table 2

Bayesian inference results.

Dow-Jones PM PSD 𝜙 0 . 5 𝜙 m i n 𝜙 m a x IF

𝛿 0.052 0.041 0.054 −0.048 0.103 3.001
𝜑 0.812 0.082 0.854−0.992 0.999 2.115
𝜑 2 𝑢 0.010 0.034 0.013 0.002 0.018 1.509
𝜔 0.405 0.071 0.461 0.004 0.816 2.367
𝛼 0.152 0.040 0.291 0.001 0.873 1.048
𝛽 0.651 0.168 0.629 0.003 0.984 2.994
𝛾 0.392 0.112 0.393 −0.681 0.418 5.108

FTSE PM PSD 𝜙 0 . 5 𝜙 m i n 𝜙 m a x IF

𝛿 0.059 0.036 0.059 −0.051 0.395 3.111
𝜑 0.811 0.096 0.839 −0.809 0.999 2.154
𝜑 2 𝑢 0.009 0.029 0.012 0.005 0.017 1.995
𝜔 0.205 0.087 0.398 0.003 0.995 1.457
𝛼 0.140 0.055 0.187 0.001 0.931 3.458
𝛽 0.682 0.153 0.701 0.001 0.988 2.721
𝛾 0.374 0.102 0.381 −0.615 0.401 1.254

Nikkei PM PSD 𝜙 0 . 5 𝜙 m i n 𝜙 m a x IF

𝛿 0.068 0.051 0.068 −0.064 0.211 2.998
𝜑 0.809 0.090 0.837 −0.831 0.999 1.211
𝜑 2 𝑢 0.010 0.031 0.010 0.004 0.019 2.001
𝜔 0.195 0.079 0.228 0.004 0.501 2.789
𝛼 0.149 0.052 0.197 0.001 0.893 3.974
𝛽 0.634 0.119 0.645 0.006 0.989 1.988
𝛾 0.408 0.123 0.409−0.587 0.487 4.007

Note: PM denotes posterior mean, PSD posterior standard deviation, 𝜙 0 . 5 posterior median, 𝜙 m i n posterior minimum, 𝜙 m a x posterior maximum, and IF inefficiency factor.