On the other hand, in the same line of text (pg.
The authors could enrich the results’ part with reference to the concepts of convergence of Barro and Sala-i-Martin, beta and sigma convergence. The authors wrote about these concepts, for example pg. 6 lines 22-23 and pg. 9 lines 5-6, but they can point out the non existence in the case of Chinese prefectural level.