The authors could enrich the results’ part with reference to the concepts of convergence of Barro and Sala-i-Martin, beta and sigma convergence.
One of the most interesting issues of the paper is the political change in 2004. Perhaps, more detailed reasons of the reform would enrich the causes to promote it. Besides, the implications of this political reform are explained in the text, but more detail in these explanations would permit to understand better these changes.