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Re: Visualizations of trade structures by Carl Nordlund 19 March 2002 02:45 UTC |
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btw: the optimal distances between the actors (ie the forces that push and pull the actors in the graph) are established through this formula: distance=scaling/(sqrt(trading volume)) A short distance therefore implies high trading volumes and a long distance implies low trading volumes. The data used covers all product groups (as I understand it) between all pairs of countries in the data set. > -----Ursprungligt meddelande----- > Fran: Carl Nordlund [mailto:carl.nordlund@humecol.lu.se] > Skickat: den 19 mars 2002 03:43 > Till: wsn@csf.colorado.edu > Amne: Visualizations of trade structures > > > Hello wsn list, > > I previously asked if anyone had any trade statistics available - > I got many helpful replies, thanks for these! I am in great debt > to professor Quee-Young Kim for the data I have used so far. > > I am currently experimenting a little on how trade statistics > might be visualized graphically, in order to simplify the > identification of possible structural exchange relations between > economies. I have now imported the data for a set of countries > for two periods - 1980 and 1995 - into a small computer program > where I am using a spring-balance technique for balancing and > positioning of actors in the network. It is written as a java > applet and is run through an ordinary web browser - at this URL: > > http://www.demesta.com/carl/temp/graph/td80_95.html > > Use the buttons at the bottom to start, stop and restore the scenario. > > The crosshair in the middle is the average coordinate for the > different actors and the circle is the average distance of the > actors from this center. > > Toggling between the two time periods is done by clicking on the > "change mode"-button. The scales are somewhat different between > the two datasets - the trading volumes in 1995 were larger than > the ones in 1980 so in order to make it easier to view I have > scaled them to similar scales; similar, though not identical > scales. Please note that it is possible to drag actors with the > mouse - on some occasions (especially what regards actors close > to the perimeter) there are a couple of possible positions for > actors. (The tension variable should be as low as possible to get > the best balance in the system) > > This is just an experiment on visualization and > network-theoretical methods so I'm not very sure whether the > graph is very informative or not; I am still a bit unsure on how > to interpret the graph! However, I do think that the actors which > establish positions at the center are usually regarded as core > countries within the modern world-system and I also believe it is > possible to identify clusters of regional trading partners. > > I would very much appreciate your comment on this, not only from > the feasibility of the visualization at hand but also comments > regarding what similar experiments have been done before and how > the world(-)system(s) community look at quantitative methods in > general as a complement to the more qualitative reasoning mostly > found in traditional dependency/world-system analysis. Comments > and feedback in general would also be most welcome. > > Yours, > Carl > - - - > Carl nordlund, PhD student > carl.nordlund@humecol.lu.se <mailto:carl.nordlund@humecol.lu.se> > Human Ecology Division, Lund University, Sweden > www.humecol.lu.se >
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