UK parliamentary boundary review 2016-2018

[jimrtex]

The review is under way. There is already plenty of discussion in the UK at http://vote-2012.proboards.com/board/2/boundaries and the official website (containing the rules and data) is at http://boundarycommissionforengland.independent.gov.uk/

If you have a feeling of deja vu, it's because the UK had a similar review 5 years ago, but it was eventually shelved.

Are the changes in registered voters among the four countries due to actual demographic change, or to the quality of the registration roles.

Change from 2011-2015:

England -3.2%
Wales -5.1%
Scotland -1.1%
Northern Ireland +2.5%

[jimrtex]

England, Wales and Scotland have seen the introduction of Individual Electoral Registration, which has the side effect of reducing the number on the register. Northern Ireland introduced IER about 15 years ago.

I was looking at these, and am even more confused.

Electoral Statistics for UK

Doing some quick Goo-research it appears that persons on the household register were able to vote in 2015. But the change appeared to occur in 2014 in England and Wales, and 2015 in Scotland.

England (2011-2015): +0.6%, -0.6%, -2.0%, -1.1% = -3.2%
Scotland (2011-2015): +1.1%, +1.1%, +0.2%, -3.4% = -1.1%
Wales (2011-2015): +0.1%, -0.2%, -3.1%, -2.0% = -5.1%

So while Scotland had the smallest drop from 2011-2015, it had the largest drop from 2014-2015. Is this related to the 2014 referendum?