Going to school, crossing borders (1): visualizing student movements between London LEAs


Figure 1: Cross Border Flows of Students into and out of London 2010-11 (Fruchtman Rheingold Layout, no filter, Modularity Analysis)

Last year I produced a few visualizations of cross-border flows of students moving across Local Education Authority boundaries across the Greater London area and have been meaning to write a blogpost on them for a while. Looking at these cross-border movements provides a broad picture of the geography of student movements between different parts of the capital. It is a loose proxy for geography of school choice too, but only to indicate broad sub-regional movements.

Nationally, London is exceptional in the high proportion of students living in one LEA and going to school in another. The only area that is vaguely similar are the Greater Manchester authorities, where there is also significant movement across borough boundaries. This has implications for funding for LEAs, with money following students. Moreover, it also reveals patterns which may be related to a lack of supply in school places, the reputation of schools in particular boroughs and of course the relatively fluid and easily-crossable boundaries of LEAs in large conurbations.

For fun, and because it is useful for my PhD(!), I started playing around with Gephi the social network package to visualize the movement of secondary school students in the academic year 2010-2011 (http://bit.ly/CrsBrdr10-11). The data is for students who are either educated in or reside in London, hence the ‘outlier’, and outlying, LEA’s like Medway, West Sussex and so forth.  I’m still experimenting with this, so any thoughts are welcome. All three figures show the movement of students living in one borough but attending school in another. The size of nodes is relative to the percentage of students attending school in their The direction of the arrow indicates the movement of students, the thickness of the arrow the number of students. Unfortunately Gephi does not allow a legend for edge thickness but to give you some idea, the largest flow of students is from Greenwich to Bexley with 2887 students. Figure 1 uses the Fruchtman Rheingold algorithm to produce the particle-like layout shown above. Figures 2 and 3 are arranged approximately by geographical location of the different boroughs.


Figure 2: Cross Border Flows of Students into and out of London 2010-11 (Approximate Geographical Layout, no filter, Modularity Analysis)


Figure 3: Cross Border Flows of Students into and out of London 2010-11 (Approximate Geographical Layout, filter: students >=50, Modularity Analysis)

You’ll notice that the LEAs, the ‘nodes’, are grouped by colour. This relates to a modularity analysis which examines community structure of the network. In this case the concentration of edges reflects those LEAs which have more links (i.e. movements of students) between each other. The analysis seems to suggest the existence of ‘sub-regional circuits of schooling’, as the educational market of school choice in London crosses borough boundaries but remains partially constrained by geographical regions and transport links (Butler and Hamnett, 2011: 40, 179). These modularity groups change slightly if the smaller flows of 50 students or less are filtered out (see Figure 3) . However, I would argue that the North-West boroughs of Harrow, Barnet, Brent and Herts are more closely linked to themselves and other central Northern boroughs than to the Western sub-regional circuit. Moreover, showing the small flows is important, given that these are likely to be students who are opting out of local provision for distinctive reasons, such as attending a grammar school instead of their local inner-city school.

On the basis of local knowledge and previous research we can suggest some potential reasons behind these movements. For example, whilst attainment at GCSE in boroughs like Hackney is now improving, at the time (early to mid-2000s) of secondary school choice for many of the students in the visualization above, attainment was only just beginning to improve and remained amongst the lowest in London (http://bbc.in/1otSmIg, see also Butler and Hamnett 2010: 2437) . This probably contributed to the considerable movement of students from Hackney into Islington and in turn from Islington into Camden. In the case of Haringey, faith schools in Enfield are, or at least were, an attractive prospect to parents from Tottenham (catchment areas using 2008/09 data for these schools are visible on educationprofiler.org/?catchment).  The existence of selective schools in Outer London and the Home Counties with very large or historical catchment areas also explains some of the stranger and smaller movements of students. Dame Alice Owen in Potters Bar has its historical roots in Angel, explaining the outward movement of a small number of students from Islington to Hertfordshire each year.

There is much scope for further examination of this data and also the use of Social Network Analysis programmes like gephi for examining educational patterns (For one example in Chile, see: Donoso Diaz and Arias Rojas, 2012). To end on a political note however, the data which these analyses has used is no longer being produced. The DfE scrapped the production of cross-border flows after the data for the 2011-12 academic year. Presumably this was a Govian cull of data production reflecting cuts in departmental budgets, but I am guessing here (there was a consultation and a small number of LEAs responded wanting to keep the data). Moreover, with London’s secondary school system managed less and less at LEA-level as academization proceeds, it will be interesting to see how issues like cross-border flows are resolved (if at all).


Butler, T. and C. Hamnett (2010). “‘You take what you are given’: the limits to parental choice in education in east London.” Environment and planning. A 42(10): 2431.

Butler, T., et al. (2011). Ethnicity, class and aspiration: understanding London’s New East End, The Policy Press.

Donoso Díaz, S. and Ó. Arias Rojas (2012). “Distribución desigual de las oportunidades educativas en el territorio y migración de la matrícula escolar: el caso de la región de Los Lagos (Chile).” Estudios pedagógicos (Valdivia) 38(2): 35-54.