In one or two paragraphs, describe one problem that helped lead to the fall of the Roman Empire. Are there any lessons that modern nations could learn to avoid this problem?

Ifound this on google “the existence of agglomeration economies is central to the explanation of how cities increase in size and population, which places the phenomenon on a larger scale. the concentration of economic activity in cities is one reason for their development and growth.” i hope this you for what your looking for.