Changes are in the works

Well, I’m back from my holiday, suitably sunburned and (relatively) relaxed. As Francis mentions, I was off in the Mediterranean somewhere (Majorca, specifically) suffering from miserable internet withdrawal symptoms. I did manage to get IRC up-and-running over dialup for election night, though this turned out to be surprisingly expensive. For once I was grateful to my iBook, which did actually Just Work when plugged into the wall.

Anyway, today’s job is sorting out the new Scottish constituency boundaries. Scotland’s Parliament was dissolved in 1707 on the passing of the Act of Union, to be reconstituted in 1999. The quid pro quo for the Scots was enhanced representation in the House of Commons; Scottish constituencies had, in 1998, an average of 55,000 electors, compared to 69,000 in England. This anomaly has now been corrected, reducing the number of constituencies in Scotland from 72 to 59; all but three of the latter have different boundaries.

This means updating MaPit, the component we built to map postcodes into electoral geography, to deal with the new boundaries. Ideally the way that we’d do this is to wait for Ordnance Survey to ship us, via our friends in ODPM, the new revision of their Boundary-Line (TM, apparently) product, with the outlines of the new constituencies encoded in attractive machine-readable form, and feed it to our existing import scripts. (As so often in life, it’s not quite that simple, but you get the general idea.) In an ideal world, this would also contain all the changed boundaries of the English counties and their constituent county electoral divisions.

However, this is not an ideal world, and though there is a new revision of Boundary-Line in the works, it hasn’t come out yet, so we have to construct the point-to-constituency mapping in some other way. Happily, at this stage of the boundary revision process, the constituency boundaries are coterminous with ward boundaries, so it’s possible to just lift the definitions of the new constituencies from the relevant Statutory Instrument and fix up the constituencies from the ward boundaries, which haven’t changed. This, sadly, has occasioned a bit of a hack to our code, because we generally don’t assume that electoral geography is hierarchically defined — because it isn’t.

(I don’t feel too bad about committing this hack, actually, because we’re likely to chuck the whole MaPit database and reconstruct it later in the year from OS data. When we built it originally, we did so from data in ESRI shapefile format; unfortunately, OS stuffed up the process of generating this from their own, internal and quite bonkers, NTF format, so the various area ID numbers in the database are not unique and not expected to be stable. We’d rather like stable ID numbers, so that we can cope gracefully with revisions to geography while maintaining continuity of, for instance, statistical data about MPs, so next time round we’re going to work from the NTF instead.)

Sadly this Scottish hack doesn’t get us anywhere with the new county boundaries, and OS have told us that not all of the updated counties will be included in the forthcoming Boundary-Line revision. So it’ll be back to the tedious conversion of statutory instruments into SQL at some point in the near future, except that we’ll probably have to start building things up from parishes, rather than wards. Expect more anguished posts on this in the future.

Meanwhile, Francis and Tom are collecting names and contact details for the new MPs. Tom tells me that this intake looks much more tech-savvy than the last, which could be good news from our (and everyone else’s) point of view. Hopefully WriteToThem will be cranking back into action — as far as MPs go, at least — fairly soon.