The Silk Road: A Review Essay on Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present. by Christopher I. Beckwith (Princeton University Press, 2009).
Abstract: This paper contains an overview of earlier research on city and empire growth/decline phases and new evidence on the relationship between urban growth and the rise and fall of empires in six world regions. We find that empires and cities grow and decline together in some regions but not others. We also examine the temporal correlations between growth/decline phases of largest and second largest cities and empires within regions. Do large empires grow at the expense of other large states within a region or are there periods of regional growth in which states (and cities) are growing together?