Thursday, March 13, 2008

Measuring the rate of cultural and social change   posted by Razib @ 3/13/2008 08:21:00 PM

Below I discussed the issue of whether the Roman Empire's decline & fall was consequential. These sorts of discussions are loaded with presuppositions and impressions. Any one metric is not necessarily representative of other variables, and one must ask whether metrics are relevant in the first case. I think one important question to ask far upstream is this: does the rate of cultural change vary? In other words, does the first derivative of a cultural variable as a function of time deviate from zero? I think it does. For example, it seems that the period between 1950-1965 witnessed less change on average and in totality in the Zeitgeist than that between 1965-1970. In other words, someone in 1965 would recognize the general outlines of the society as less alien 15 years before than 5 years into the future.

With that assumption under the belt, the question we might ask about the Roman Empire is this: was there a discontinuity in the change so that one could say that the barbarian invasions were very significant? Or did the classical world of late antiquity slowly melt into the early medieval period. Most everyone can agree that production, material and intellectual, tended to decrease. But was the 6th century, for example, a period of particularly sharp decline in Italy? Traditional narrative history has a story to tell about the disruptive impact of the wars between the Goths and the East Roman Empire; that in the process of reconquering Italy Justinian destroyed it.

But enough. I have a copy of Contours of the World Economy 1-2030 AD, which has a handy chapter on the economy of the Roman Empire. Below the fold I've reformatted some of the population data to put it out on the web.

Population in 000s

200 BC1 AD200 AD400 AD600 AD



Roman Gaul44005750750057504500


Danubian lands25503050355034502600

Roman Europe1895022800255502070015400

Asia Minor50006000700060005000

Greater Syria26003025275022001900


Roman Asia78009250995084007100




Roman Africa65008200950079006800


200 BC - 1 AD 1 AD - 200 AD 200 AD - 400 AD 400 AD - 600 AD



Roman Gaul13501750-1750-1250


Danubian lands500500-100-850

Roman Europe38502750-4850-5300

Asia Minor10001000-1000-1000

Greater Syria425-275-550-300


Roman Asia1450700-1550-1300




Roman Africa17001300-1600-1100


200 BC - 1 AD1 AD - 200 AD200 AD - 400 AD400 AD - 600 AD



Roman Gaul30.68%30.43%-23.33%-21.74%


Danubian lands19.61%16.39%-2.82%-24.64%

Roman Europe20.32%12.06%-18.98%-25.60%

Asia Minor20.00%16.67%-14.29%-16.67%

Greater Syria16.35%-9.09%-20.00%-13.64%


Roman Asia18.59%7.57%-15.58%-15.48%




Roman Africa26.15%15.85%-16.84%-13.92%


A few thoughts? First, look at Greece. The Roman Empire wasn't so hot for it, but remember that prior to the conquest of this region it was a major center of Hellenistic civilization under the Macedonians. Italy's economic boom was in large part based on plunder, and Greece's no longer (in fact, Greece was one of the major sources of high value slaves for Italy). Also, the data points hide a lot in between. During the mid-200s the Roman Empire nearly collapsed, and by 300 it had been resurrected by a series of reforms under the emperor Diocletian. So the difference between the year 200 and 400 likely masks that there might have been a minimum point sometime late in the 200s. Finally, you can see some regional dynamics. The recovery of the late 3rd century was under the aegis of emperors derived from the Danubian provinces, so the relative robustness between 200-400 can be attributed to the likelihood that the military and cultural outlays enabled by increased taxation benefited these regions via redistribution.