Social Science History Association November 12-15 2009

1. synchrony and networkshow the growth and decline of cities and the rise and fall of city-size hierarchies is related to the network structure of intercity connectionsDoug White UC Irvine Social Science History Association November 12-15 2009

2. Parts of the story in a nutshell Pax Mongolica: The routes of the silk road leading west from Central Asia (detail of map at Tashkent University). http://www.silk-road.com/artl/paxmongolica.shtml Temporally: Opening and closure of the silk roads affect globalized Eurasian synchrony from China to Europe Economic structure: The bicomponent multiple independent routes between cities as the trading nodes promote competitive pricing. City rise and city-fall: Population scaling distributions change with temporal changes in economic links. Cycles vs. cutpoints are key to the dynamics as polities compete for dominance of trading routes and cities.

3. Parts of the story in a nutshell Pax Mongolica: The routes are subject to policies of polities and empires, falling into epochs of domination (Modelski et al. p.78,217)___Regional N. Sung 930- S. Sung 1060- Genoa 1190-_________to Global____ Mongols 1250-90-1360 trans Eurasian Portugal 1430- Global system mapping Holland 1540- Global capital England 1640- Global industrial exports Britain 1740- Global organization United States 1850-Global information- Global market United States 1950- Decolonization -1990 Depolarization - Global hyperspace

4. Euro-Hegemon examples (Arrighi 1994) Commercial Financial Constantinople Venice Genoa Amsterdam London New York

5. Transaction costs, hegemony and inflation as q-correlated temporal variables Commercial Inflation Lo/hi Financial capital Peace of Westphalia Dominant Routes Struggle for Empire: Sea Battles to 1815 Trade net (low cost) versus (high cost) Maritime (low cost) versus Land routes trade (pop. growth) Global Maritime EconomyIndustrial Rev. from 1760 Political Revolutions to 1814 Sea routes safe French Sov. Conflict on Land  Sea trade routes safer than land, 1318-1453/4+(Spufford:407) Landed Armies safe land routes 1500-1650 Maritime Conflicts (Jan Glete) Landed Trade Secure Baltic conflicts: connection to Novgorod and Russia (lost) Swedish hegemony European access

6. Conclusions: city systems in the last millennium • City systems unstable; have historical periods of rise and fall over hundreds of years; exhibit collapse. • City system growth periods in one region, which are periods of innovation, have time-lagged effects on less developed regions if there are active trade routes between them.  • NETWORKS AFFECT DEVELOPMENT. • SO WHY DOES THE MEDIEVAL EUROPEAN RENAISSANCE ECONOMY COLLAPSE CIRCA 1300? • Trade dominance shifts from betweenness centrality (Genoa) to global Flow Centrality (Bruges) • China invaded, change in Silk routes • Credit crisis between North and Southern Europe • Major problem in Population Growth/Resource base • Internecine struggles • Major collapse, long recovery "Long 13th century” reaches to today

7. Whole period 900 - 1950 Are there inter-region synchronies? Cross-correlations give lag 0 = perfect synchrony lag 1 = state of region A predicts that of B 50 years later lag 2 = state of region A predicts that of B 100 years later lag 3 = state of region A predicts that of B 150 years later etc. Cities in the region of “MiddleEast&Afghan&India” are initially inversely related to but then affect Chinese Cities with 100-150 year lags city systems in the last millennium

8. Moving to closer inter-Asian regions excluding India but on the Silk Road Time-lagged cross-correlation effects of Mid-Asian q on China (1=50 year lagged effect) MiddleEast&Afghan Robust Cities affect Robust Chinese Cities with 50 year lag city systems in the last millennium

9. Moving between endpoints further away on the Silk Roads Time-lagged cross-correlation effects of China q on Europe (100 year lagged effect) Robust Chinese Cities affect Robust European Cities with 100 and 300 year lag (non-MLE result for q) city systems in the last millennium

10. Time-lagged cross-correlation effects of the Silk Road trade on Europe (50 year lagged effect) Chinese Silk road trade affects Elite tails of European Cities with 50 year lag Robust Mideast Cities small effect on Robust European Cities with 150 year lag city systems in the last millennium

11. Elite tails of European Cities maintain Paris as Euro Elite Capital with 100 year decay

12. Probability distribution q shapes for a person being in a city with at least population x (fitted by MLE estimation)Pareto Type II Goodness of fit for q and beta10 are found by bootstrap probability simulation, where with added iterations around each of four periods q measures the shape of the body of the curve, while beta10 measure fits the log-log slope of the tails, which vary independently of q. city systems in the last millennium Shalizi (2007) right graphs=variant fits

13. Mid-Asia China Europe Variations in q and the power-law slope β for 900-1970 in 50 year intervals city systems in the last millennium

14. Are these random walks or historical Periods? Runs Test Results city systems in the last millennium

15. (figures courtesy of Andrew Sherratt, ArchAtlas) Cohesive extension of trade routes leads to a host of other developments…

16. Multiconnected regions => structural cohesion variables

17. Multiconnected regions => structural cohesion variables

18. Multiconnected regions => structural cohesion variables

19. Multiconnected regions => structural cohesion variables Some changes in the medieval network from 1000 CE

20. Multiconnected regions => structural cohesion variables to 1500 CE (note changes in biconnected zones of structural cohesion) Project mapping is proceeding for cities and trade networks for all of AfroEurasia and urban industries for Europe in 25-year intervals, 1150-1500 (our technology for cities / zones / trade networks / distributions of multiple industries across cities for each time period includes dynamic GIS overlays, flyover and zoomable web images)

21. 0900 AD From first stirrings of globalization to the 21st Century Europe Central Asia Medit. China Near East India Silk routes In these slides I will connect the city network & city size distributions and power-law tails connected to q-exponential scaling of city sizes Bagdad & Changan (Xi’an) low q with thin power law tails of global hubs CORRELATES with global network links Q (scaling sizes)

22. 1000 AD 960: Song capital at Kaifeng, invention of national markets, credit mechanisms diffuse N~3 Silk routes Global network links characterize low q (power law tail for city sizes)

23. 1100 AD Silk Routes Global network links characterize low q (more exponential body with power law tail for city sizes)

24. 1150 AD 1127: No. Song capital of Kaifeng conquered, Song move to south, capital at Hangchow Silk Routes diminish Global network links characterize low q (more exponential body with power law tail for city sizes)

25. 1200 AD Song capital at Hangchow Golden Horde silk routes Silk Routes diminish Global network links characterize low q

26. 1250 AD cutnodes edgecut Broken network links lead change to high q – led by China, 50 years

27. 1300 AD 1279: Mongols conquer Song Kublai Khan Mongol trade Broken network links characterize high q (here: tenuous interregional connectors)

28. 1350 AD Mongols refocus on Yuan administration of China Silk routes unimportant Broken network links characterize high q (here: tenuous interregional connectors)

29. 1368 Ming retake China Silk routes unimportant 1400 AD Renewed network links characterize low q (power law tail)

30. 1450 AD 1421 Ming move capital to Peking Silk routes unimportant World population growth turns super-exponential Renewed network links characterize low q (power law) – high q led by China, 100 years

31. 1500 AD Renewed network links characterize low q (power law tail) – but China high q leads change

32. 1550 AD Broken network links characterize high q

33. 1600 AD Renewed network links will lead change to low q (here: tenuous interregional connectors)

34. 1650 AD Renewed network links characterize low q (power law tail) – China synchronized

35. 1700 AD Broken network links return to high q – esp. forChina leading

36. 1750 AD Broken network links typify high q – China leading – bifurcated world

37. 1800 AD Circum-European cities start to overtake China in number Broken network links typify high q – bifurcated world

38. 1825 AD European cities overtake China in number and size Industrial revolution Broken network links typify high q – trifurcated world – best example of high local navigability British opium trade from India

39. 1850 AD Broken network links typify high q – trifurcated world – but China developing power-law tail (here: tenuous interregional connectors)

40. 1875 AD Broken network links typify high q – bifurcated - China power-law tail thinning toward low-q (here: tenuous interregional connectors)

41. 1900 AD Broken network links typify high q – trifurcated Eurodominant - China leads shift to low-q 50 yrs

42. 1925 AD Broken network links typify high q – trifurcated - rise of Japan - China returns to high q

43. 1950 AD Start of a low q Zipfian tail for world city distribution – trifurcated – but linked by airlines

44. N-cohesion (2=competitive 1=monopoly land trade) leads Q (city rise/fall) : fragments

45. Is there Eurasia synchrony? Yes: but it is not simultaneous. Rather, it is time-lagged synchrony and not always in the direction. It goes from leading to trailing economies following the dynamics of trade. And the dynamics of trade is influenced by whether the trading network is monopolized by chokepoints or is competitive. Competition is defined by biconnectivity. (A special case of structural cohesion)