1. Internet Access to Census Migration and Journey-to-Work Data John Stillwell and Oliver Duke-Williams Centre for Computational Geography University of Leeds, Leeds LS2 9JT Paper presented at the 32 nd Annual Conference of the Regional Science Association International British and Irish Section (Session on Migration Analysis) Dudley Hotel, Brighton and Hove, 21-23 August 2002

2. Focus The provision and development of a Census Interaction Data Service (CIDS)The provision and development of a Census Interaction Data Service (CIDS) The development of a web-based information system (WICID) that allows researchers to extract data on interaction flows between sets of origins and destinationsThe development of a web-based information system (WICID) that allows researchers to extract data on interaction flows between sets of origins and destinations

3. Presentation The challenge: aims and objectivesThe challenge: aims and objectives Census-based interaction data setsCensus-based interaction data sets System architectureSystem architecture Metadata structureMetadata structure Features of the interfaceFeatures of the interface Some examples of data extraction and analysisSome examples of data extraction and analysis Conclusions - next stepsConclusions - next steps

4. Acknowledgements Funded by ESRC and JISC under the 2001 Census of Population ProgrammeFunded by ESRC and JISC under the 2001 Census of Population Programme (Award number H507 255177) Began: 1 August 2001Began: 1 August 2001 Ends: 31 July 2006Ends: 31 July 2006 Paul Boyle and Zhiqiang Feng, St AndrewsPaul Boyle and Zhiqiang Feng, St Andrews

5. The Challenge To increase the use of the Origin- Destination (interaction) data sets that will be produced as outputs from the 2001 UK CensusTo increase the use of the Origin- Destination (interaction) data sets that will be produced as outputs from the 2001 UK Census (as well as the equivalent special migration and commuting data sets produced from 1991 and 1981 Censuses)

6. Objectives To provide users with access to existing census based interaction data sets (for 1991 and 1981) via the InternetTo provide users with access to existing census based interaction data sets (for 1991 and 1981) via the Internet To maintain and develop an ‘user-friendly’ interface for query building and data extractionTo maintain and develop an ‘user-friendly’ interface for query building and data extraction To develop a flexible system that allows new data sets (e.g. 2001 Census interaction data) to be added without any major system redesignTo develop a flexible system that allows new data sets (e.g. 2001 Census interaction data) to be added without any major system redesign

7. Objectives To allow users the option of constructing queries that involve the selection of origin and destination areas at different spatial scalesTo allow users the option of constructing queries that involve the selection of origin and destination areas at different spatial scales To produce a library of popular sub-sets of interaction data for quick extraction and downloadingTo produce a library of popular sub-sets of interaction data for quick extraction and downloading To provide facilities to download the data in alternative formatsTo provide facilities to download the data in alternative formats

8. Interaction Data Sets for 1991 Original data sets SMS Set 1 (2 tables, 12 counts, wards)SMS Set 1 (2 tables, 12 counts, wards) SMS Set 2 (12 tables, 93 counts, districts)SMS Set 2 (12 tables, 93 counts, districts) SWS Set C (9 tables, 274 counts, wards)SWS Set C (9 tables, 274 counts, wards) Table 100 (2 tables, 47 counts, districts)Table 100 (2 tables, 47 counts, districts) Derived data sets SMS Set 1 Tables 3-10 (adjusted by Rees and Duke-Williams) so-called SMSGAPSSMS Set 1 Tables 3-10 (adjusted by Rees and Duke-Williams) so-called SMSGAPS SMS Set 1 Table 3 (adjusted by Simpson and Middleton) so called SMS-MIGPOPSMS Set 1 Table 3 (adjusted by Simpson and Middleton) so called SMS-MIGPOP

9. Interaction Data Sets for 1981 1981 SMS Set 2 (Male and female migrants between wards in 1991)1981 SMS Set 2 (Male and female migrants between wards in 1991) 1981 SWS Set C (Five tables - 172 counts - of journey to work flows between wards in 1991)1981 SWS Set C (Five tables - 172 counts - of journey to work flows between wards in 1991) all re-estimated for 1991 ward geography by Boyle and Feng as part of a Census Development Programme projectall re-estimated for 1991 ward geography by Boyle and Feng as part of a Census Development Programme project

10. System Architecture

11. Metadata Structure

12. CIDS Homepage

13. Features of the WICID Interface Login in screen

14. General Query Screen

15. Area Selection Tools

17. List Area Selection Tool

18. Data Selection Tools

19. Data Selection Options

20. Table Selection for 1991 SMS 2

21. Variable Selection with Table 4 of the 1991 SMS 2

22. Off the shelf facility

23. Data extraction

24. WICID Output Planner

25. WICID Output Previewer

26. Some examples of data extraction What were the migrant flows to Brighton from elsewhere in 1990-91? Need to design a set of zones that are suitable: - districts in Sussex - counties in SE - other GB regions - NI and Eire - overseas

27. Query: Extraction of SMS data on migration to Brighton, 1990-91

28. Migration flows to Brighton, 1990-91

29. Query: SMS data on age-specific migration to Brighton from rest of GB and from overseas, 1990-91

30. Age profiles of in-migrants to Brighton from rest of GB and from overseas, 1990-91

31. Query: Students aged 19-21 with term-time residence in Sussex and usual residence by county

32. Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Main county origins with term-time addresses in Sussex Main county origins with term-time addresses in Sussex

33. Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Main county destinations of students with term-time address outside Sussex Main county destinations of students with term-time address outside Sussex

34. Query: Migration flows in life course ages for DTLR modelling system Query: Migration flows in life course ages for DTLR modelling system

35. Spatial Interaction Modelling Power function model: Exponential function model:

36. Decay parameters and mean migration distances

37. Parameters and MMLs for matrices that exclude intra-area flows Parameters and MMLs for matrices that include intra-area flows

38. Social structure of Leeds and surrounding districts using 1991 SWS

39. Query: Journey to work flows between zones by social class, 1991

40. Social class structure of commuters in Leeds and between Leeds and surrounding districts, 1991 Source: 1991 Census Crown Copyright: ESRC/JISC Purchase

41. Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Proportions of commuters to Central Leeds from other wards and surrounding districts by social class, 1991 Professional Managerial and Technical

42. Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Skilled Non-manual Skilled Manual

43. Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Partly Skilled Unskilled

44. Conclusions/Next steps CIDS now up and runningCIDS now up and running Flexible metadata structure of WICID will allow 2001 Census results to be included in the systemFlexible metadata structure of WICID will allow 2001 Census results to be included in the system WICID will be used to verify the 2001 data in 2003WICID will be used to verify the 2001 data in 2003 Mapping option for geographical area selection now being developedMapping option for geographical area selection now being developed Analysis and modelling facilities intended but raise difficult questionsAnalysis and modelling facilities intended but raise difficult questions