“…These studies can be grouped into three classes: 1) macro-economic type of studies using general equilibrium theories and/or input-output tables [1,36,43,78,81,96,141]; 2) econometric type of studies not addressing the issue of causality [45,48,56,79,103,104,107,108,150,160,168,169]; and 3) econometric type of studies claiming to address causality [46,68,100,151].…”