The Roman Empire lasted from 27 b.c. to a.d. 476. The empire was wealthy enough to build such monuments as the Roman Coliseum. Roman engineering skill was at a level high enough that aqueducts built during the empire to carry water long distances remained in use for hundreds of years. Yet, although the empire experienced some periods of growth in real GDP per capita, these periods did not last, and there is little evidence that growth would have been sustained even if the empire had survived.
Why didn't the Roman Empire experience sustained economic growth? What would the world be like today if it had?