1. ThisworkwascarriedoutwiththeaidofagrantfromtheInterna5onalDevelopmentResearchCentre,O>awa,Canada. Understandingsocialconnec/ons KaushalyaMadhawa,LIRNEasia Responsibleuseofmobilemeta-datatosupportpublicpurposes JetwingLagoon,Negombo 08August2014

2. Understanding social connections Canweiden5fycommuni5esofpeopleusing socialconnec5ons? Docommunica5onpa>ernsrevealthesocio- economicstatusofapopula5on? Arepeoplescommunica5onandmobility pa>ernsco-related? 1 3. Understanding social connections Canweiden5fycommuni5esofpeopleusing socialconnec5ons? Docommunica5onpa>ernsrevealthesocio- economicstatusofapopula5on? Arepeoplescommunica5onandmobility pa>ernsco-related? 2 4. What is a community? Acommunityisagroupofpeoplewhohave strongerintra-groupconnec5onsthaninter-group connec5ons 3 5. So we asked: Doadministra5veboundariesbasedonhistoryand geographyreectactualcommuni5esin2014? Howcanmobilenetworkbigdatabeusedto iden5fytheseactualcommuni5es? 4 6. What are the administrative boundaries in Sri Lanka? 9Provinces 25Districts 331Divisional Secretariat Divisions(DSD) 14021Grama NiladhariDivisions (GND) 5 7. What are the administrative boundaries in Sri Lanka? 9Provinces 25Districts 331Divisional Secretariat Divisions(DSD) 14021Grama NiladhariDivisions (GND) 6 8. What are the administrative boundaries in Sri Lanka? 9Provinces 25Districts 331Divisional Secretariat Divisions(DSD) 14021Grama NiladhariDivisions (GND) 7 9. What are the administrative boundaries in Sri Lanka? 9Provinces 25Districts 331Divisional Secretariat Divisions(DSD) 14021Grama NiladhariDivisions (GND) 8 10. Which DSD talks to which DSD? Eachlinkrepresents therawnumberof outgoingand incomingcalls betweentwoDSDs No. of calls Low High 9 11. A different picture emerges when call volume is normalized by population Stronglyconnected componentsarevisible No. of calls Low High 10 12. Identifying communities 11 13. Identifying communities: methodology Thesocialnetworkissegregatedsuchthat overlappingconnec5onsbetween communi5esareminimized. Strengthofacommunityisdeterminedby modularity ModularityQ= (edgesinsidethecommunity) (expectednumberofedgesinsidethecommunity) M.E.J.-Newman,Michele-Girvan,Findingandevalua5ngcommunitystructureinnetworks,PhysicalReviewE,APS,Vol.69,No.2,p.1-16,204. 12 14. Actual communities found by the algorithm Thecommuni5eswefoundare centeredaroundgeographic neighbourhoods. ForSriLanka,theop5mal numberofcommuni5es discoveredbythealgorithm was11 13 15. Actual communities found by the algorithm SouthernandNorthern provinceshavethehighest similaritytotheirrespec5ve provincialboundaries. Colombodistrictisclusteredas asinglecommunityand GampahaismergedwithNorth WesternProvince 14 16. Actual communities found by the algorithm SouthernandNorthern provinceshavethehighest similaritytotheirrespec5ve provincialboundaries. Colombodistrictisclusteredas asinglecommunityand GampahaismergedwithNorth WesternProvince 15 17. Zooming into a community Community detection is done within identified communities These communities are less less related to DSD boundaries in Colombo district 16 18. How communities are connected Communityconsis5ngofNorthernprovince hadtheleastconnectednesswithother communi5es. Communityconsis5ngofRatnapuradistrict andapartofKegalleisthemostconnected community. 17 19. How communities are connected with each other Region Connectedness (%) 1. Ratnapura, South Kegalle, North Eastern Colombo 74 2.Badulla, Monaragala 71 3. Anuradhapura, East Kurunegala, North Matale 71 4.Kalutara 70 5. Gampaha, Puttalam, West Kurunegala 65 6.Trincomalee 65 7.Kandy, Nuwara Eliya, North Kegalle, South Matale 63 8.Colombo without North Eastern part belongs that now belongs to 1 63 9. Galle, Matara, Hambantota 62 10. Batticaloa, Polonnaruwa, Ampara 60 11. Jaffna, Kilinochchi, Mannar, Mullaitivu 56 11 10 9 7 8 6 1 2 3 4 5 connectednesswithothercommunities Low High 18 20. Future work Exploretherela5onshipbetweensocial networkcommuni5esandtheirmobility proles Understandthedistribu5onofsocio- economicstatuswithincommuni5es 19