In this study, I also use the approaches of Ram (1988) and Zhang (2001) to
determine the sign of short-run Granger causality. The sign of short-run Granger
causality from an independent variable to the dependent variable is determined by
adding up the coefficients of all lagged first differences of the independent variable. If
the summation of these coefficients provides a positive value, the independent
variable has positive effects on the dependent variable in the short-run. The selected
value of n is 1 for equation (6). Therefore, only one lagged first difference of GDPP is
introduced in equation (6). The estimated coefficient of DGDPt1 in this equation is
0.000154 suggesting that the sign of this unidirectional short-run Granger causality
running from GDPP to OFDI is positive