But surely the point is that, if we want to set up new fiscal arrangements between the constituent parts of the United Kingdom, we should not do it on the basis of assumptions. We should do it on the basis of hard facts, and one of the conclusions of the book is that we need to do more hard research and assign revenues and spending on a territorial basis. Such proposals are not in the Bill, but I hope that the Government will take those matters forward.
I shall give the House an example to illustrate why there would be a huge debate about the revenue. Let us take Standard Life, which is headquartered in Edinburgh. If corporation tax were devolved, the company would be domiciled as Scottish, yet it trades throughout the United Kingdom and has many policyholders in England who contribute to its profits. How would we determine which profits were Scottish and which were English? These are huge issues and they would have to be resolved before a full system of fiscal autonomy could be introduced.