where Yt denoted a k 1 vector of k endogenous variables, α
represented a k 1 vector of constants (intercept), βi was a k p
Fig. 3. Gold prices for the past ten years (US$/ Ounce).
H.-F. Chang et al. / Energy Policy 63 (2013) 441–448 443
matrix (for every i¼1,…, p), εt denoted an independent random
error with EðεtÞ ¼ 0 and VarðεtÞ was a constant.