Before revision:  Investigation of the determining factors shows that roughly the same explanatory variables are important in all models, with regulatory quality,  GDP per capita and unemployment rate as common important variables.
After revision:  Investigation of the determining factors shows that there is some heterogeneity in the important variables across the models. However, the two models with the highest out-of-sample predictive accuracy, MLP and CART, show a lot of similarities in the influential variables, with regulatory quality, GDP per capita and unemployment rate as common important variables.