In addition, we also employ dynamic panel GMM estimation (Arellano and Bond, 1991) and the system GMM estimation (Arellano and Bover, 1995) to eliminate any endogeneity that may appear, if any, because of the correlation of these country-specific effects, and to get rid of country-specific effects and time-invariant country-specific variable, and ensure that all the regressors are stationary (Baltagi et al., 2009).