My Lords, the Bill provides for an equalisation in constituencies so that their electorates have to fall within bands of plus or minus 5 per cent, with only two exceptions. This amendment proposes a small but important change that that should be not plus or minus 5 per cent of the electorates but plus or minus 5 per cent of a notional electorate, which is calculated to provide for shortfalls in registration.
I will turn to the substance of the argument in a minute, but I want to make one point that pervaded our earlier debates and which, as the House's resident statistical geek, rather grates on me: the tendency of people to prefer an exact figure, however ill based and peculiar, to an estimated figure, however well calculated. The fact is that the registered electorate is a very poor figure indeed for calculating anything. I will come to the detail in a minute, but will say now that only 91 to 92 per cent of the actual electorate are registered. Some 3.5 million people are missing from the electoral register. We all want better registration, but it will not come in an instant. So it is not really a good figure.
I cannot help but contrast the imprecision of that number-not that it is a precise number; it is a meaningless number-with the precision of the 5 per cent that is allowed each way. I have argued in various contexts that the Bill is too inflexible for the purpose that we all share, which is equalising the size of constituencies. That led me to wonder whether there was not a way of coming up with a notional figure for electorates that more nearly reflected both up-to-date figures and the actuality of the number of should-be electors in each constituency that also deals with non-registration.
I remind the Committee of the figures. Non-registration is very serious, but it is concentrated in particular groups. The Electoral Commission published in March 2010 a study, The Completeness and Accuracy of Electoral Registers in Great Britain. The figures given in it are striking: 56 per cent of 17 to 24 year-olds are not registered. Of private sector tenants, 49 per cent are not registered. Of people from black and ethnic minorities, 31 per cent are not registered. That distorts the figures on which we are trying to base size of constituency in the future.
If those figures are soundly based-everyone can look at the Electoral Commission's study and see how soundly based they think they are, but it seemed a good piece of work to me-it would be possible to construct mathematically and with no great difficulty a model that provided a decent estimate of what the electorate in each constituency would be if everyone who is eligible to register had done so. This would have certain effects. For example, it would mean that inner-city areas tended to have rather more representation, while stable suburban areas had rather less.
There are various advantages to this. First, MPs represent everyone. Therefore, an estimate of the notional electorate-actually, the number of people who really live in their areas-would be nearer to the number of everyone whom they represented than the actual registered electorate. Secondly, it would be a more robust measure in a system of registration that will have great noise and perhaps instability injected into it. In principle, individual registration is a great thing. As we know from Northern Ireland, the reality, at least at first, can be very different from the theory.