You can’t always get what you want… but if you try sometimes you might just find… you get what you need.

Now with that song firmly playing as my mental soundtrack for the day, I’ll explain: it’s a rare thing to find the exact data you need for a research task, but sometimes you can get what you need another way. We call it proxy data, and it works on the principle that if you didn’t have summer temperature data, say, you could measure the sales of barbecues to give you a good idea of the weather pattern.

Inward migration to the UK is an example. With open borders within the EU and it being a long time since the 2001 Census, the influx of migrants during the last decade is a matter of estimation only. However, other information can give us a view on the patterns of movement over a decade which saw ten new member states join the EU in 2004 and a booming UK economy draw in motivated and qualified economic migrants to particular areas of the country – until the economy shuddered to a halt.

Source: NHS data via ONS

The map above visualises annual new registrations with GPs (family doctors) per 1000 population in the districts of England and Wales between 2000 and 2010, where the previous address of the registrant was outside the UK. The darkest shade indicates more than 60 per 1000 in a given year. All kudos to my colleague Gaynor who recalled that ‘Flag 4′ as the non-UK address is called is such a useful nugget of insight.

She has then animated the maps to illustrate the dynamic shift over the decade, starting with 2000-01 and showing each year before looping back to the beginning. A couple of patterns are worth highlighting (see below).

Of course, this isn’t a perfect proxy, since not every migrant will register with a GP, and we’d expect a skew in these data towards people arriving with families and those intending to stay for some time.

Throughout as you’d expect, the urban centres show the highest rates of new registrants, but early on we can detect higher numbers per 1000 population arriving in East Anglia and Lincolnshire, with some warm spots emerging in the midlands and further west as the years go by. By 2004 East Cambridgeshire, Peterborough and the Lincolnshire districts of South Holland and Boston clearly emerge with faster rates of new registrants – an area popular with migrant workers.

The rate of new registrations in this area peaks at a rate over 30 per 1000 in 2007-08, and we all remember what happened then: the beginning of the banking crisis, the credit crunch and the slowdown of the economy. Sure enough, the rates of inward migration start to slow down, no doubt as the relative merits of hard farm labouring jobs near the Wash and skilled manufacturing for the German market rapidly shifted.

Two other twists intrigue me: what’s occurring in West Wales at the end of the decade? And how come Oxford and Cambridge have such constant high levels of registration? I’d expect high levels of overseas arrivals in both cities, but are there no other university towns where the rate is so high relative to their resident populations?

I studied in Cambridge myself (a few years ago now) and we were required by university rules to register with a doctor – they didn’t leave it to the choice of feckless teenagers – was this so for students arriving over the last ten years but not in other institutions? And can a rule like this really be behind an observable national data pattern?

Companies, government bodies and charities use our work to reveal insights like these and make strategic decisions based on them. And the comments, questions and local knowledge prompted by mapping data are all captured via easy to use tools.

We don’t just make animating maps – but sometimes they are exactly what you need.

Mark Thurstain-Goodwin